21903136 has 12 divisors (see below), whose sum is σ = 43121862. Its totient is φ = 10951552.

The previous prime is 21903131. The next prime is 21903169. The reversal of 21903136 is 63130912.

It can be written as a sum of positive squares in only one way, i.e., 21566736 + 336400 = 4644^2 + 580^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21903136.

It is not an unprimeable number, because it can be changed into a prime (21903131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342205 + ... + 342268.

Almost surely, 2^21903136 is an apocalyptic number.

It is an amenable number.

21903136 is a deficient number, since it is larger than the sum of its proper divisors (21218726).

21903136 is an equidigital number, since it uses as much as digits as its factorization.

21903136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684483 (or 684475 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 21903136 is about 4680.0786318181. The cubic root of 21903136 is about 279.7920905564.

The spelling of 21903136 in words is "twenty-one million, nine hundred three thousand, one hundred thirty-six".