77944325513 has 2 divisors, whose sum is σ = 77944325514. Its totient is φ = 77944325512.

The previous prime is 77944325509. The next prime is 77944325531. The reversal of 77944325513 is 31552344977.

Together with next prime (77944325531) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 77890111744 + 54213769 = 279088^2 + 7363^2 .

It is a cyclic number.

It is not a de Polignac number, because 77944325513 - 2² = 77944325509 is a prime.

It is not a weakly prime, because it can be changed into another prime (77944328513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38972162756 + 38972162757.

It is an arithmetic number, because the mean of its divisors is an integer number (38972162757).

Almost surely, 2^77944325513 is an apocalyptic number.

It is an amenable number.

77944325513 is a deficient number, since it is larger than the sum of its proper divisors (1).

77944325513 is an equidigital number, since it uses as much as digits as its factorization.

77944325513 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3175200, while the sum is 50.

The spelling of 77944325513 in words is "seventy-seven billion, nine hundred forty-four million, three hundred twenty-five thousand, five hundred thirteen".