77679997 has 4 divisors (see below), whose sum is σ = 77704540. Its totient is φ = 77655456.

The previous prime is 77679977. The next prime is 77680003. The reversal of 77679997 is 79997677.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30702681 + 46977316 = 5541^2 + 6854^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77679997 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 (77679977) 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, 6672 + ... + 14137.

It is an arithmetic number, because the mean of its divisors is an integer number (19426135).

Almost surely, 2^77679997 is an apocalyptic number.

It is an amenable number.

77679997 is a deficient number, since it is larger than the sum of its proper divisors (24543).

77679997 is a wasteful number, since it uses less digits than its factorization.

77679997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24542.

The product of its digits is 10501974, while the sum is 61.

The square root of 77679997 is about 8813.6256444213. The cubic root of 77679997 is about 426.6807666103.

The spelling of 77679997 in words is "seventy-seven million, six hundred seventy-nine thousand, nine hundred ninety-seven".