77680645 has 32 divisors (see below), whose sum is σ = 112896000. Its totient is φ = 50124096.

The previous prime is 77680601. The next prime is 77680651. The reversal of 77680645 is 54608677.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-77680645 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 132042 + ... + 132628.

It is an arithmetic number, because the mean of its divisors is an integer number (3528000).

Almost surely, 2^77680645 is an apocalyptic number.

It is an amenable number.

77680645 is a deficient number, since it is larger than the sum of its proper divisors (35215355).

77680645 is a wasteful number, since it uses less digits than its factorization.

77680645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 817.

The product of its (nonzero) digits is 282240, while the sum is 43.

The square root of 77680645 is about 8813.6624056064. The cubic root of 77680645 is about 426.6819530520.

The spelling of 77680645 in words is "seventy-seven million, six hundred eighty thousand, six hundred forty-five".