20730979 has 2 divisors, whose sum is σ = 20730980. Its totient is φ = 20730978.

The previous prime is 20730947. The next prime is 20730991. The reversal of 20730979 is 97903702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20730979 - 2⁵ = 20730947 is a prime.

It is not a weakly prime, because it can be changed into another prime (20730079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10365489 + 10365490.

It is an arithmetic number, because the mean of its divisors is an integer number (10365490).

Almost surely, 2^20730979 is an apocalyptic number.

20730979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20730979 is an equidigital number, since it uses as much as digits as its factorization.

20730979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23814, while the sum is 37.

The square root of 20730979 is about 4553.1284848991. The cubic root of 20730979 is about 274.7092420007.

The spelling of 20730979 in words is "twenty million, seven hundred thirty thousand, nine hundred seventy-nine".