21264364 has 12 divisors (see below), whose sum is σ = 40595688. Its totient is φ = 9665600.

The previous prime is 21264361. The next prime is 21264371. The reversal of 21264364 is 46346212.

It is not an unprimeable number, because it can be changed into a prime (21264361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241597 + ... + 241684.

It is an arithmetic number, because the mean of its divisors is an integer number (3382974).

Almost surely, 2^21264364 is an apocalyptic number.

It is an amenable number.

21264364 is a deficient number, since it is larger than the sum of its proper divisors (19331324).

21264364 is a wasteful number, since it uses less digits than its factorization.

21264364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483296 (or 483294 counting only the distinct ones).

The product of its digits is 6912, while the sum is 28.

The square root of 21264364 is about 4611.3299600007. The cubic root of 21264364 is about 277.0453079193.

The spelling of 21264364 in words is "twenty-one million, two hundred sixty-four thousand, three hundred sixty-four".