21895172 has 24 divisors (see below), whose sum is σ = 43060416. Its totient is φ = 9665568.

The previous prime is 21895169. The next prime is 21895177. The reversal of 21895172 is 27159812.

It is not an unprimeable number, because it can be changed into a prime (21895177) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7958 + ... + 10349.

It is an arithmetic number, because the mean of its divisors is an integer number (1794184).

Almost surely, 2^21895172 is an apocalyptic number.

It is an amenable number.

21895172 is a deficient number, since it is larger than the sum of its proper divisors (21165244).

21895172 is a wasteful number, since it uses less digits than its factorization.

21895172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18347 (or 18345 counting only the distinct ones).

The product of its digits is 10080, while the sum is 35.

The square root of 21895172 is about 4679.2277140571. The cubic root of 21895172 is about 279.7581755601.

The spelling of 21895172 in words is "twenty-one million, eight hundred ninety-five thousand, one hundred seventy-two".