195715777979 has 2 divisors, whose sum is σ = 195715777980. Its totient is φ = 195715777978.

The previous prime is 195715777951. The next prime is 195715777981. The reversal of 195715777979 is 979777517591.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-195715777979 is a prime.

It is a Sophie Germain prime.

Together with 195715777981, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (195715777909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97857888989 + 97857888990.

It is an arithmetic number, because the mean of its divisors is an integer number (97857888990).

Almost surely, 2^195715777979 is an apocalyptic number.

195715777979 is a deficient number, since it is larger than the sum of its proper divisors (1).

195715777979 is an equidigital number, since it uses as much as digits as its factorization.

195715777979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 306307575, while the sum is 74.

The spelling of 195715777979 in words is "one hundred ninety-five billion, seven hundred fifteen million, seven hundred seventy-seven thousand, nine hundred seventy-nine".