21365164 has 6 divisors (see below), whose sum is σ = 37389044. Its totient is φ = 10682580.

The previous prime is 21365159. The next prime is 21365173. The reversal of 21365164 is 46156312.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2670642 + ... + 2670649.

Almost surely, 2^21365164 is an apocalyptic number.

It is an amenable number.

21365164 is a deficient number, since it is larger than the sum of its proper divisors (16023880).

21365164 is a wasteful number, since it uses less digits than its factorization.

21365164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5341295 (or 5341293 counting only the distinct ones).

The product of its digits is 4320, while the sum is 28.

The square root of 21365164 is about 4622.2466398928. The cubic root of 21365164 is about 277.4823796403.

The spelling of 21365164 in words is "twenty-one million, three hundred sixty-five thousand, one hundred sixty-four".