77886716381 has 2 divisors, whose sum is σ = 77886716382. Its totient is φ = 77886716380.

The previous prime is 77886716363. The next prime is 77886716387. The reversal of 77886716381 is 18361768877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55240981156 + 22645735225 = 235034^2 + 150485^2 .

It is an emirp because it is prime and its reverse (18361768877) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 77886716381 - 2⁶ = 77886716317 is a prime.

It is a super-2 number, since 2×77886716381² (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 (77886716387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38943358190 + 38943358191.

It is an arithmetic number, because the mean of its divisors is an integer number (38943358191).

Almost surely, 2^77886716381 is an apocalyptic number.

It is an amenable number.

77886716381 is a deficient number, since it is larger than the sum of its proper divisors (1).

77886716381 is an equidigital number, since it uses as much as digits as its factorization.

77886716381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18966528, while the sum is 62.

The spelling of 77886716381 in words is "seventy-seven billion, eight hundred eighty-six million, seven hundred sixteen thousand, three hundred eighty-one".