77969378665 has 16 divisors (see below), whose sum is σ = 93873459600. Its totient is φ = 62169044992.

The previous prime is 77969378639. The next prime is 77969378689. The reversal of 77969378665 is 56687396977.

It can be written as a sum of positive squares in 8 ways, for example, as 14564627856 + 63404750809 = 120684^2 + 251803^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77969378665 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1836801 + ... + 1878769.

It is an arithmetic number, because the mean of its divisors is an integer number (5867091225).

Almost surely, 2^77969378665 is an apocalyptic number.

It is an amenable number.

77969378665 is a deficient number, since it is larger than the sum of its proper divisors (15904080935).

77969378665 is a wasteful number, since it uses less digits than its factorization.

77969378665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43196.

The product of its digits is 720135360, while the sum is 73.

The spelling of 77969378665 in words is "seventy-seven billion, nine hundred sixty-nine million, three hundred seventy-eight thousand, six hundred sixty-five".