77656505413 has 2 divisors, whose sum is σ = 77656505414. Its totient is φ = 77656505412.

The previous prime is 77656505369. The next prime is 77656505419. The reversal of 77656505413 is 31450565677.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74759590084 + 2896915329 = 273422^2 + 53823^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77656505413 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77656505419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38828252706 + 38828252707.

It is an arithmetic number, because the mean of its divisors is an integer number (38828252707).

Almost surely, 2^77656505413 is an apocalyptic number.

It is an amenable number.

77656505413 is a deficient number, since it is larger than the sum of its proper divisors (1).

77656505413 is an equidigital number, since it uses as much as digits as its factorization.

77656505413 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2646000, while the sum is 49.

The spelling of 77656505413 in words is "seventy-seven billion, six hundred fifty-six million, five hundred five thousand, four hundred thirteen".