77985715969 has 32 divisors (see below), whose sum is σ = 99392956416. Its totient is φ = 59614874880.

The previous prime is 77985715957. The next prime is 77985715987. The reversal of 77985715969 is 96951758977.

It is a cyclic number.

It is not a de Polignac number, because 77985715969 - 2³⁵ = 43625977601 is a prime.

It is a super-2 number, since 2×77985715969² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (77985715949) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 159714 + ... + 426004.

It is an arithmetic number, because the mean of its divisors is an integer number (3106029888).

Almost surely, 2^77985715969 is an apocalyptic number.

It is an amenable number.

77985715969 is a deficient number, since it is larger than the sum of its proper divisors (21407240447).

77985715969 is a wasteful number, since it uses less digits than its factorization.

77985715969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266445.

The product of its digits is 300056400, while the sum is 73.

The spelling of 77985715969 in words is "seventy-seven billion, nine hundred eighty-five million, seven hundred fifteen thousand, nine hundred sixty-nine".