20979824 has 10 divisors (see below), whose sum is σ = 40648440. Its totient is φ = 10489904.

The previous prime is 20979809. The next prime is 20979877. The reversal of 20979824 is 42897902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 655604 + ... + 655635.

It is an arithmetic number, because the mean of its divisors is an integer number (4064844).

Almost surely, 2^20979824 is an apocalyptic number.

It is an amenable number.

20979824 is a deficient number, since it is larger than the sum of its proper divisors (19668616).

20979824 is a wasteful number, since it uses less digits than its factorization.

20979824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1311247 (or 1311241 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 41.

The square root of 20979824 is about 4580.3737838740. The cubic root of 20979824 is about 275.8040336852.

The spelling of 20979824 in words is "twenty million, nine hundred seventy-nine thousand, eight hundred twenty-four".