21664062 has 24 divisors (see below), whose sum is σ = 53644656. Its totient is φ = 6189696.

The previous prime is 21664051. The next prime is 21664063. The reversal of 21664062 is 26046612.

It is a happy number.

21664062 is a `hidden beast` number, since 2 + 16 + 640 + 6 + 2 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21664063) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85843 + ... + 86094.

It is an arithmetic number, because the mean of its divisors is an integer number (2235194).

Almost surely, 2^21664062 is an apocalyptic number.

21664062 is an abundant number, since it is smaller than the sum of its proper divisors (31980594).

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

21664062 is a wasteful number, since it uses less digits than its factorization.

21664062 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171952 (or 171949 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21664062 is about 4654.4668867659. The cubic root of 21664062 is about 278.7703818541.

The spelling of 21664062 in words is "twenty-one million, six hundred sixty-four thousand, sixty-two".