21620727 has 24 divisors (see below), whose sum is σ = 33446400. Its totient is φ = 13417488.

The previous prime is 21620723. The next prime is 21620737. The reversal of 21620727 is 72702612.

It is not a de Polignac number, because 21620727 - 2² = 21620723 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21620727.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21620723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9018 + ... + 11160.

It is an arithmetic number, because the mean of its divisors is an integer number (1393600).

Almost surely, 2^21620727 is an apocalyptic number.

21620727 is a deficient number, since it is larger than the sum of its proper divisors (11825673).

21620727 is a wasteful number, since it uses less digits than its factorization.

21620727 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2227 (or 2224 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 21620727 is about 4649.8093509304. The cubic root of 21620727 is about 278.5843813645.

The spelling of 21620727 in words is "twenty-one million, six hundred twenty thousand, seven hundred twenty-seven".