77944325509 has 2 divisors, whose sum is σ = 77944325510. Its totient is φ = 77944325508.

The previous prime is 77944325489. The next prime is 77944325513. The reversal of 77944325509 is 90552344977.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 59372632225 + 18571693284 = 243665^2 + 136278^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77944325509 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77944325509.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (77944325579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38972162754 + 38972162755.

It is an arithmetic number, because the mean of its divisors is an integer number (38972162755).

Almost surely, 2^77944325509 is an apocalyptic number.

It is an amenable number.

77944325509 is a deficient number, since it is larger than the sum of its proper divisors (1).

77944325509 is an equidigital number, since it uses as much as digits as its factorization.

77944325509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9525600, while the sum is 55.

The spelling of 77944325509 in words is "seventy-seven billion, nine hundred forty-four million, three hundred twenty-five thousand, five hundred nine".