21385264 has 10 divisors (see below), whose sum is σ = 41433980. Its totient is φ = 10692624.

The previous prime is 21385253. The next prime is 21385283. The reversal of 21385264 is 46258312.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 668274 + ... + 668305.

It is an arithmetic number, because the mean of its divisors is an integer number (4143398).

Almost surely, 2^21385264 is an apocalyptic number.

It is an amenable number.

21385264 is a deficient number, since it is larger than the sum of its proper divisors (20048716).

21385264 is a wasteful number, since it uses less digits than its factorization.

21385264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1336587 (or 1336581 counting only the distinct ones).

The product of its digits is 11520, while the sum is 31.

The square root of 21385264 is about 4624.4203961145. The cubic root of 21385264 is about 277.5693693416.

The spelling of 21385264 in words is "twenty-one million, three hundred eighty-five thousand, two hundred sixty-four".