# 400

## Nearby Numbers

Positive, nonzero integers within three units

397
Three Hundred and Ninety-Seven
398
Three Hundred and Ninety-Eight
399
Three Hundred and Ninety-Nine
401
Four Hundred and One
402
Four Hundred and Two
403
Four Hundred and Three

## Scientific Notation

Scientific notation expresses a quantity as the product of its significand with 10 raised to an integer exponent.

## Reciprocal

A number multiplied with its reciprocal is one.

### `0.0025`

The reciprocal of 400.

## Palindrome?

A numerical palindrome has the same value when all of its digits are reversed.

The number 400 is not a palindrome.

## Not A Prime Number

A prime number is a positive integer that is divisible only by itself and one.

Four hundred is a composite number with 15 total factors (including 1 and itself).   See primes in Base 10 Decimal

## A Composite

Composites have more than just these two factors.

Four hundred is a composite number with 15 total factors (including 1 and itself).

## Prime Factors

The prime factors of a positive integer are the integers that divide it exactly and are also prime.

The number four hundred has the following 2 prime factors:

2
Two
5
Five

## Prime Factorization

The prime factorization of a positive integer is the unique list of prime factors together with their multiplicities

## Base Conversions

The number four hundred in 35 different bases