20979959 has 16 divisors (see below), whose sum is σ = 28170240. Its totient is φ = 15089760.

The previous prime is 20979949. The next prime is 20979961. The reversal of 20979959 is 95997902.

It is not a de Polignac number, because 20979959 - 2⁴ = 20979943 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20979929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9479 + ... + 11480.

It is an arithmetic number, because the mean of its divisors is an integer number (1760640).

Almost surely, 2^20979959 is an apocalyptic number.

20979959 is a deficient number, since it is larger than the sum of its proper divisors (7190281).

20979959 is a wasteful number, since it uses less digits than its factorization.

20979959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20990.

The product of its (nonzero) digits is 459270, while the sum is 50.

The square root of 20979959 is about 4580.3885206388. The cubic root of 20979959 is about 275.8046252609.

It can be divided in two parts, 20 and 979959, that added together give a palindrome (979979).

The spelling of 20979959 in words is "twenty million, nine hundred seventy-nine thousand, nine hundred fifty-nine".