77864718731 has 2 divisors, whose sum is σ = 77864718732. Its totient is φ = 77864718730.

The previous prime is 77864718697. The next prime is 77864718781. The reversal of 77864718731 is 13781746877.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77864718731 - 2¹⁸ = 77864456587 is a prime.

It is a super-2 number, since 2×77864718731² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (77864718781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38932359365 + 38932359366.

It is an arithmetic number, because the mean of its divisors is an integer number (38932359366).

Almost surely, 2^77864718731 is an apocalyptic number.

77864718731 is a deficient number, since it is larger than the sum of its proper divisors (1).

77864718731 is an equidigital number, since it uses as much as digits as its factorization.

77864718731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11063808, while the sum is 59.

The spelling of 77864718731 in words is "seventy-seven billion, eight hundred sixty-four million, seven hundred eighteen thousand, seven hundred thirty-one".