21425800 has 48 divisors (see below), whose sum is σ = 54349200. Its totient is φ = 7790400.

The previous prime is 21425783. The next prime is 21425801. The reversal of 21425800 is 852412.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is not an unprimeable number, because it can be changed into a prime (21425801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2670 + ... + 7069.

It is an arithmetic number, because the mean of its divisors is an integer number (1132275).

Almost surely, 2^21425800 is an apocalyptic number.

21425800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21425800 is an abundant number, since it is smaller than the sum of its proper divisors (32923400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21425800 is a wasteful number, since it uses less digits than its factorization.

21425800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9766 (or 9757 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 21425800 is about 4628.8011406843. The cubic root of 21425800 is about 277.7446372315.

The spelling of 21425800 in words is "twenty-one million, four hundred twenty-five thousand, eight hundred".