77736688969 has 3 divisors (see below), whose sum is σ = 77736967783. Its totient is φ = 77736410156.

The previous prime is 77736688903. The next prime is 77736689027. The reversal of 77736688969 is 96988663777.

The square root of 77736688969 is 278813.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1443620025 + 76293068944 = 37995^2 + 276212^2 .

It is not a de Polignac number, because 77736688969 - 2⁹ = 77736688457 is a prime.

It is a super-2 number, since 2×77736688969² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77736688895 and 77736688904.

It is not an unprimeable number, because it can be changed into a prime (77736688769) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 139407 + ... + 418219.

Almost surely, 2^77736688969 is an apocalyptic number.

77736688969 is the 278813-rd square number.

77736688969 is the 139407-th centered octagonal number.

It is an amenable number.

77736688969 is a deficient number, since it is larger than the sum of its proper divisors (278814).

77736688969 is an frugal number, since it uses more digits than its factorization.

77736688969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557626 (or 278813 counting only the distinct ones).

The product of its digits is 1152216576, while the sum is 76.

The spelling of 77736688969 in words is "seventy-seven billion, seven hundred thirty-six million, six hundred eighty-eight thousand, nine hundred sixty-nine".