20756979 has 20 divisors (see below), whose sum is σ = 31305120. Its totient is φ = 13705200.

The previous prime is 20756977. The next prime is 20756993. The reversal of 20756979 is 97965702.

It is not a de Polignac number, because 20756979 - 2¹ = 20756977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20756977) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 7654 + ... + 10004.

It is an arithmetic number, because the mean of its divisors is an integer number (1565256).

Almost surely, 2^20756979 is an apocalyptic number.

20756979 is a deficient number, since it is larger than the sum of its proper divisors (10548141).

20756979 is a wasteful number, since it uses less digits than its factorization.

20756979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2472 (or 2463 counting only the distinct ones).

The product of its (nonzero) digits is 238140, while the sum is 45.

The square root of 20756979 is about 4555.9827699411. The cubic root of 20756979 is about 274.8240372940.

The spelling of 20756979 in words is "twenty million, seven hundred fifty-six thousand, nine hundred seventy-nine".