20979944 has 16 divisors (see below), whose sum is σ = 40080420. Its totient is φ = 10291840.

The previous prime is 20979943. The next prime is 20979949. The reversal of 20979944 is 44997902.

It can be written as a sum of positive squares in 2 ways, for example, as 20811844 + 168100 = 4562^2 + 410^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20979895 and 20979904.

It is not an unprimeable number, because it can be changed into a prime (20979943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24317 + ... + 25164.

Almost surely, 2^20979944 is an apocalyptic number.

It is an amenable number.

20979944 is a deficient number, since it is larger than the sum of its proper divisors (19100476).

20979944 is a wasteful number, since it uses less digits than its factorization.

20979944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49540 (or 49536 counting only the distinct ones).

The product of its (nonzero) digits is 163296, while the sum is 44.

The square root of 20979944 is about 4580.3868832229. The cubic root of 20979944 is about 275.8045595304.

The spelling of 20979944 in words is "twenty million, nine hundred seventy-nine thousand, nine hundred forty-four".