20356979 has 2 divisors, whose sum is σ = 20356980. Its totient is φ = 20356978.

The previous prime is 20356943. The next prime is 20356991. The reversal of 20356979 is 97965302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20356979 - 2⁸ = 20356723 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20356279) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10178489 + 10178490.

It is an arithmetic number, because the mean of its divisors is an integer number (10178490).

Almost surely, 2^20356979 is an apocalyptic number.

20356979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20356979 is an equidigital number, since it uses as much as digits as its factorization.

20356979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 102060, while the sum is 41.

The square root of 20356979 is about 4511.8708979757. The cubic root of 20356979 is about 273.0472307107.

The spelling of 20356979 in words is "twenty million, three hundred fifty-six thousand, nine hundred seventy-nine".