21812732 has 12 divisors (see below), whose sum is σ = 38632776. Its totient is φ = 10774800.

The previous prime is 21812731. The next prime is 21812737. The reversal of 21812732 is 23721812.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21812731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32519 + ... + 33182.

It is an arithmetic number, because the mean of its divisors is an integer number (3219398).

Almost surely, 2^21812732 is an apocalyptic number.

It is an amenable number.

21812732 is a deficient number, since it is larger than the sum of its proper divisors (16820044).

21812732 is a wasteful number, since it uses less digits than its factorization.

21812732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65788 (or 65786 counting only the distinct ones).

The product of its digits is 1344, while the sum is 26.

The square root of 21812732 is about 4670.4102603519. The cubic root of 21812732 is about 279.4066175281.

It can be divided in two parts, 2181 and 2732, that added together give a cube (4913 = 17³).

The spelling of 21812732 in words is "twenty-one million, eight hundred twelve thousand, seven hundred thirty-two".