77702371385 has 4 divisors (see below), whose sum is σ = 93242845668. Its totient is φ = 62161897104.

The previous prime is 77702371381. The next prime is 77702371423. The reversal of 77702371385 is 58317320777.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 40262830336 + 37439541049 = 200656^2 + 193493^2 .

It is a cyclic number.

It is not a de Polignac number, because 77702371385 - 2² = 77702371381 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77702371381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7770237134 + ... + 7770237143.

It is an arithmetic number, because the mean of its divisors is an integer number (23310711417).

Almost surely, 2^77702371385 is an apocalyptic number.

It is an amenable number.

77702371385 is a deficient number, since it is larger than the sum of its proper divisors (15540474283).

77702371385 is a wasteful number, since it uses less digits than its factorization.

77702371385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15540474282.

The product of its (nonzero) digits is 1728720, while the sum is 50.

The spelling of 77702371385 in words is "seventy-seven billion, seven hundred two million, three hundred seventy-one thousand, three hundred eighty-five".