21625975 has 24 divisors (see below), whose sum is σ = 30855168. Its totient is φ = 14728800.

The previous prime is 21625963. The next prime is 21625979. The reversal of 21625975 is 57952612.

It is not a de Polignac number, because 21625975 - 2⁹ = 21625463 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21625979) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33102 + ... + 33748.

It is an arithmetic number, because the mean of its divisors is an integer number (1285632).

Almost surely, 2^21625975 is an apocalyptic number.

21625975 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21625975 is a deficient number, since it is larger than the sum of its proper divisors (9229193).

21625975 is a wasteful number, since it uses less digits than its factorization.

21625975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 855 (or 850 counting only the distinct ones).

The product of its digits is 37800, while the sum is 37.

The square root of 21625975 is about 4650.3736409024. The cubic root of 21625975 is about 278.6069198073.

The spelling of 21625975 in words is "twenty-one million, six hundred twenty-five thousand, nine hundred seventy-five".