21925020 has 48 divisors (see below), whose sum is σ = 66114720. Its totient is φ = 5396736.

The previous prime is 21925009. The next prime is 21925021. The reversal of 21925020 is 2052912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21925021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13275 + ... + 14834.

It is an arithmetic number, because the mean of its divisors is an integer number (1377390).

Almost surely, 2^21925020 is an apocalyptic number.

21925020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21925020 is an abundant number, since it is smaller than the sum of its proper divisors (44189700).

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

21925020 is a wasteful number, since it uses less digits than its factorization.

21925020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28134 (or 28132 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 21925020 is about 4682.4160430274. The cubic root of 21925020 is about 279.8852420886.

Adding to 21925020 its reverse (2052912), we get a palindrome (23977932).

The spelling of 21925020 in words is "twenty-one million, nine hundred twenty-five thousand, twenty".