77947431669 has 6 divisors (see below), whose sum is σ = 112590734646. Its totient is φ = 51964954440.

The previous prime is 77947431637. The next prime is 77947431713. The reversal of 77947431669 is 96613474977.

77947431669 is a `hidden beast` number, since 7 + 79 + 474 + 31 + 6 + 69 = 666.

It can be written as a sum of positive squares in only one way, i.e., 54580640625 + 23366791044 = 233625^2 + 152862^2 .

It is not a de Polignac number, because 77947431669 - 2⁵ = 77947431637 is a prime.

It is a super-2 number, since 2×77947431669² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77947431769) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4330412862 + ... + 4330412879.

It is an arithmetic number, because the mean of its divisors is an integer number (18765122441).

Almost surely, 2^77947431669 is an apocalyptic number.

It is an amenable number.

77947431669 is a deficient number, since it is larger than the sum of its proper divisors (34643302977).

77947431669 is a wasteful number, since it uses less digits than its factorization.

77947431669 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8660825747 (or 8660825744 counting only the distinct ones).

The product of its digits is 48009024, while the sum is 63.

The spelling of 77947431669 in words is "seventy-seven billion, nine hundred forty-seven million, four hundred thirty-one thousand, six hundred sixty-nine".