21675216 has 40 divisors (see below), whose sum is σ = 56228544. Its totient is φ = 7194880.

The previous prime is 21675211. The next prime is 21675239. The reversal of 21675216 is 61257612.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21675211) 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, 12685 + ... + 14291.

Almost surely, 2^21675216 is an apocalyptic number.

It is an amenable number.

21675216 is an abundant number, since it is smaller than the sum of its proper divisors (34553328).

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

21675216 is a wasteful number, since it uses less digits than its factorization.

21675216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1899 (or 1893 counting only the distinct ones).

The product of its digits is 5040, while the sum is 30.

The square root of 21675216 is about 4655.6649363974. The cubic root of 21675216 is about 278.8182163946.

The spelling of 21675216 in words is "twenty-one million, six hundred seventy-five thousand, two hundred sixteen".