77038719521 has 2 divisors, whose sum is σ = 77038719522. Its totient is φ = 77038719520.

The previous prime is 77038719509. The next prime is 77038719523. The reversal of 77038719521 is 12591783077.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74114073121 + 2924646400 = 272239^2 + 54080^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77038719521 is a prime.

Together with 77038719523, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77038719521.

It is not a weakly prime, because it can be changed into another prime (77038719523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 38519359760 + 38519359761.

It is an arithmetic number, because the mean of its divisors is an integer number (38519359761).

Almost surely, 2^77038719521 is an apocalyptic number.

It is an amenable number.

77038719521 is a deficient number, since it is larger than the sum of its proper divisors (1).

77038719521 is an equidigital number, since it uses as much as digits as its factorization.

77038719521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 740880, while the sum is 50.

The spelling of 77038719521 in words is "seventy-seven billion, thirty-eight million, seven hundred nineteen thousand, five hundred twenty-one".