21874536 has 40 divisors (see below), whose sum is σ = 61270770. Its totient is φ = 7291296.

The previous prime is 21874513. The next prime is 21874537. The reversal of 21874536 is 63547812.

It can be written as a sum of positive squares in only one way, i.e., 17589636 + 4284900 = 4194^2 + 2070^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 21874536.

It is not an unprimeable number, because it can be changed into a prime (21874537) by changing a digit.

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 9 ways as a sum of consecutive naturals, for example, 16231 + ... + 17526.

Almost surely, 2^21874536 is an apocalyptic number.

It is an amenable number.

21874536 is an abundant number, since it is smaller than the sum of its proper divisors (39396234).

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

21874536 is a wasteful number, since it uses less digits than its factorization.

21874536 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33775 (or 33762 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 21874536 is about 4677.0221295179. The cubic root of 21874536 is about 279.6702580905.

The spelling of 21874536 in words is "twenty-one million, eight hundred seventy-four thousand, five hundred thirty-six".