21375264 has 24 divisors (see below), whose sum is σ = 56110320. Its totient is φ = 7125056.

The previous prime is 21375253. The next prime is 21375293. The reversal of 21375264 is 46257312.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×21375264² = 913803822139392, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 111234 + ... + 111425.

It is an arithmetic number, because the mean of its divisors is an integer number (2337930).

Almost surely, 2^21375264 is an apocalyptic number.

21375264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21375264 is an abundant number, since it is smaller than the sum of its proper divisors (34735056).

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

21375264 is a wasteful number, since it uses less digits than its factorization.

21375264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222672 (or 222664 counting only the distinct ones).

The product of its digits is 10080, while the sum is 30.

The square root of 21375264 is about 4623.3390531087. The cubic root of 21375264 is about 277.5260976998.

The spelling of 21375264 in words is "twenty-one million, three hundred seventy-five thousand, two hundred sixty-four".