21682636 has 12 divisors (see below), whose sum is σ = 38111920. Its totient is φ = 10793520.

The previous prime is 21682627. The next prime is 21682643. The reversal of 21682636 is 63628612.

It is a happy number.

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

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 3 ways as a sum of consecutive naturals, for example, 10920 + ... + 12751.

Almost surely, 2^21682636 is an apocalyptic number.

It is an amenable number.

21682636 is a deficient number, since it is larger than the sum of its proper divisors (16429284).

21682636 is a wasteful number, since it uses less digits than its factorization.

21682636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23904 (or 23902 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 21682636 is about 4656.4617468632. The cubic root of 21682636 is about 278.8500283826.

The spelling of 21682636 in words is "twenty-one million, six hundred eighty-two thousand, six hundred thirty-six".