77720685 has 32 divisors (see below), whose sum is σ = 150481152. Its totient is φ = 33438720.

The previous prime is 77720663. The next prime is 77720693. The reversal of 77720685 is 58602777.

It is not a de Polignac number, because 77720685 - 2⁷ = 77720557 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, 19986 + ... + 23555.

It is an arithmetic number, because the mean of its divisors is an integer number (4702536).

Almost surely, 2^77720685 is an apocalyptic number.

It is an amenable number.

77720685 is a deficient number, since it is larger than the sum of its proper divisors (72760467).

77720685 is a wasteful number, since it uses less digits than its factorization.

77720685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43573.

The product of its (nonzero) digits is 164640, while the sum is 42.

The square root of 77720685 is about 8815.9335864105. The cubic root of 77720685 is about 426.7552506364.

The spelling of 77720685 in words is "seventy-seven million, seven hundred twenty thousand, six hundred eighty-five".