20392979 has 4 divisors (see below), whose sum is σ = 21592584. Its totient is φ = 19193376.

The previous prime is 20392963. The next prime is 20392987. The reversal of 20392979 is 97929302.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20392979 - 2⁴ = 20392963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20392279) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 599777 + ... + 599810.

It is an arithmetic number, because the mean of its divisors is an integer number (5398146).

Almost surely, 2^20392979 is an apocalyptic number.

20392979 is a deficient number, since it is larger than the sum of its proper divisors (1199605).

20392979 is a wasteful number, since it uses less digits than its factorization.

20392979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1199604.

The product of its (nonzero) digits is 61236, while the sum is 41.

The square root of 20392979 is about 4515.8586116042. The cubic root of 20392979 is about 273.2080913767.

The spelling of 20392979 in words is "twenty million, three hundred ninety-two thousand, nine hundred seventy-nine".