21365166 has 32 divisors (see below), whose sum is σ = 43960320. Its totient is φ = 6919136.

The previous prime is 21365159. The next prime is 21365173. The reversal of 21365166 is 66156312.

It is an interprime number because it is at equal distance from previous prime (21365159) and next prime (21365173).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67240 + ... + 67556.

It is an arithmetic number, because the mean of its divisors is an integer number (1373760).

Almost surely, 2^21365166 is an apocalyptic number.

21365166 is an abundant number, since it is smaller than the sum of its proper divisors (22595154).

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

21365166 is a wasteful number, since it uses less digits than its factorization.

21365166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 608.

The product of its digits is 6480, while the sum is 30.

The square root of 21365166 is about 4622.2468562378. The cubic root of 21365166 is about 277.4823882987.

The spelling of 21365166 in words is "twenty-one million, three hundred sixty-five thousand, one hundred sixty-six".