21634766 has 16 divisors (see below), whose sum is σ = 34120224. Its totient is φ = 10268544.

The previous prime is 21634741. The next prime is 21634799. The reversal of 21634766 is 66743612.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4586 + ... + 8018.

It is an arithmetic number, because the mean of its divisors is an integer number (2132514).

Almost surely, 2^21634766 is an apocalyptic number.

21634766 is a deficient number, since it is larger than the sum of its proper divisors (12485458).

21634766 is a wasteful number, since it uses less digits than its factorization.

21634766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3595.

The product of its digits is 36288, while the sum is 35.

The square root of 21634766 is about 4651.3187377345. The cubic root of 21634766 is about 278.6446661075.

The spelling of 21634766 in words is "twenty-one million, six hundred thirty-four thousand, seven hundred sixty-six".