21386732 has 18 divisors (see below), whose sum is σ = 37860732. Its totient is φ = 10570744.

The previous prime is 21386713. The next prime is 21386747. The reversal of 21386732 is 23768312.

It is a happy number.

Its product of digits (12096) is a multiple of the sum of its prime divisors (576).

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 5 ways as a sum of consecutive naturals, for example, 45563 + ... + 46029.

It is an arithmetic number, because the mean of its divisors is an integer number (2103374).

Almost surely, 2^21386732 is an apocalyptic number.

It is an amenable number.

21386732 is a deficient number, since it is larger than the sum of its proper divisors (16474000).

21386732 is a wasteful number, since it uses less digits than its factorization.

21386732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 685 (or 576 counting only the distinct ones).

The product of its digits is 12096, while the sum is 32.

The square root of 21386732 is about 4624.5791159845. The cubic root of 21386732 is about 277.5757204831.

The spelling of 21386732 in words is "twenty-one million, three hundred eighty-six thousand, seven hundred thirty-two".