77757720631 has 2 divisors, whose sum is σ = 77757720632. Its totient is φ = 77757720630.

The previous prime is 77757720617. The next prime is 77757720679. The reversal of 77757720631 is 13602775777.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 77757720631 - 2²¹ = 77755623479 is a prime.

It is a super-2 number, since 2×77757720631² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77757727631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38878860315 + 38878860316.

It is an arithmetic number, because the mean of its divisors is an integer number (38878860316).

Almost surely, 2^77757720631 is an apocalyptic number.

77757720631 is a deficient number, since it is larger than the sum of its proper divisors (1).

77757720631 is an equidigital number, since it uses as much as digits as its factorization.

77757720631 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3025260, while the sum is 52.

The spelling of 77757720631 in words is "seventy-seven billion, seven hundred fifty-seven million, seven hundred twenty thousand, six hundred thirty-one".