21660488 has 32 divisors (see below), whose sum is σ = 41583360. Its totient is φ = 10575360.

The previous prime is 21660479. The next prime is 21660491. The reversal of 21660488 is 88406612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 79793 + ... + 80063.

It is an arithmetic number, because the mean of its divisors is an integer number (1299480).

Almost surely, 2^21660488 is an apocalyptic number.

It is an amenable number.

21660488 is a deficient number, since it is larger than the sum of its proper divisors (19922872).

21660488 is a wasteful number, since it uses less digits than its factorization.

21660488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 477 (or 473 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 35.

The square root of 21660488 is about 4654.0829386679. The cubic root of 21660488 is about 278.7550510859.

The spelling of 21660488 in words is "twenty-one million, six hundred sixty thousand, four hundred eighty-eight".