21572925 has 48 divisors (see below), whose sum is σ = 39521280. Its totient is φ = 10296000.

The previous prime is 21572911. The next prime is 21572933. The reversal of 21572925 is 52927512.

It is a happy number.

It is not a de Polignac number, because 21572925 - 2⁴ = 21572909 is a prime.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 65010 + ... + 65340.

It is an arithmetic number, because the mean of its divisors is an integer number (823360).

Almost surely, 2^21572925 is an apocalyptic number.

21572925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21572925 is a deficient number, since it is larger than the sum of its proper divisors (17948355).

21572925 is a wasteful number, since it uses less digits than its factorization.

21572925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 434 (or 429 counting only the distinct ones).

The product of its digits is 12600, while the sum is 33.

The square root of 21572925 is about 4644.6662958710. Note that the first 3 decimals coincide. The cubic root of 21572925 is about 278.3789193106.

The spelling of 21572925 in words is "twenty-one million, five hundred seventy-two thousand, nine hundred twenty-five".