77688479957 has 4 divisors (see below), whose sum is σ = 84751069056. Its totient is φ = 70625890860.

The previous prime is 77688479927. The next prime is 77688479959. The reversal of 77688479957 is 75997488677.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 77688479957 - 2²⁴ = 77671702741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77688479959) 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, 3531294533 + ... + 3531294554.

It is an arithmetic number, because the mean of its divisors is an integer number (21187767264).

Almost surely, 2^77688479957 is an apocalyptic number.

It is an amenable number.

77688479957 is a deficient number, since it is larger than the sum of its proper divisors (7062589099).

77688479957 is a wasteful number, since it uses less digits than its factorization.

77688479957 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7062589098.

The product of its digits is 1493614080, while the sum is 77.

The spelling of 77688479957 in words is "seventy-seven billion, six hundred eighty-eight million, four hundred seventy-nine thousand, nine hundred fifty-seven".