21920264 has 16 divisors (see below), whose sum is σ = 41209020. Its totient is φ = 10931200.

The previous prime is 21920263. The next prime is 21920279. The reversal of 21920264 is 46202912.

It can be written as a sum of positive squares in 2 ways, for example, as 21548164 + 372100 = 4642^2 + 610^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21920263) 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 in 3 ways as a sum of consecutive naturals, for example, 209 + ... + 6624.

Almost surely, 2^21920264 is an apocalyptic number.

It is an amenable number.

21920264 is a deficient number, since it is larger than the sum of its proper divisors (19288756).

21920264 is a wasteful number, since it uses less digits than its factorization.

21920264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7240 (or 7236 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 21920264 is about 4681.9081580057. The cubic root of 21920264 is about 279.8650029512.

The spelling of 21920264 in words is "twenty-one million, nine hundred twenty thousand, two hundred sixty-four".