1918117979 has 2 divisors, whose sum is σ = 1918117980. Its totient is φ = 1918117978.

The previous prime is 1918117961. The next prime is 1918118011. The reversal of 1918117979 is 9797118191.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1918117979 - 2²⁰ = 1917069403 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1918117979.

It is not a weakly prime, because it can be changed into another prime (1918117909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 959058989 + 959058990.

It is an arithmetic number, because the mean of its divisors is an integer number (959058990).

Almost surely, 2^1918117979 is an apocalyptic number.

1918117979 is a deficient number, since it is larger than the sum of its proper divisors (1).

1918117979 is an equidigital number, since it uses as much as digits as its factorization.

1918117979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 53.

The square root of 1918117979 is about 43796.3238069133. The cubic root of 1918117979 is about 1242.4867670619.

The spelling of 1918117979 in words is "one billion, nine hundred eighteen million, one hundred seventeen thousand, nine hundred seventy-nine".