18571979 has 2 divisors, whose sum is σ = 18571980. Its totient is φ = 18571978.

The previous prime is 18571963. The next prime is 18571991. The reversal of 18571979 is 97917581.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 18571979 - 2⁴ = 18571963 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (18574979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9285989 + 9285990.

It is an arithmetic number, because the mean of its divisors is an integer number (9285990).

Almost surely, 2^18571979 is an apocalyptic number.

18571979 is a deficient number, since it is larger than the sum of its proper divisors (1).

18571979 is an equidigital number, since it uses as much as digits as its factorization.

18571979 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 47.

The square root of 18571979 is about 4309.5218992366. The cubic root of 18571979 is about 264.8211870717.

The spelling of 18571979 in words is "eighteen million, five hundred seventy-one thousand, nine hundred seventy-nine".