21604662 has 48 divisors (see below), whose sum is σ = 48542208. Its totient is φ = 6940080.

The previous prime is 21604643. The next prime is 21604669. The reversal of 21604662 is 26640612.

It is a happy number.

It is a super-2 number, since 2×21604662² = 933522840268488, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21604669) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79587 + ... + 79857.

It is an arithmetic number, because the mean of its divisors is an integer number (1011296).

Almost surely, 2^21604662 is an apocalyptic number.

21604662 is an abundant number, since it is smaller than the sum of its proper divisors (26937546).

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

21604662 is a wasteful number, since it uses less digits than its factorization.

21604662 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 422 counting only the distinct ones).

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

The square root of 21604662 is about 4648.0815397323. The cubic root of 21604662 is about 278.5153647672.

The spelling of 21604662 in words is "twenty-one million, six hundred four thousand, six hundred sixty-two".