21620732 has 12 divisors (see below), whose sum is σ = 43241520. Its totient is φ = 9266016.

The previous prime is 21620723. The next prime is 21620737. The reversal of 21620732 is 23702612.

21620732 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 21620698 and 21620707.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620737) 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, 386057 + ... + 386112.

It is an arithmetic number, because the mean of its divisors is an integer number (3603460).

Almost surely, 2^21620732 is an apocalyptic number.

It is an amenable number.

21620732 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21620732 is a wasteful number, since it uses less digits than its factorization.

21620732 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 772180 (or 772178 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 21620732 is about 4649.8098885868. The cubic root of 21620732 is about 278.5844028396.

The spelling of 21620732 in words is "twenty-one million, six hundred twenty thousand, seven hundred thirty-two".