77989985 has 16 divisors (see below), whose sum is σ = 95212800. Its totient is φ = 61316736.

The previous prime is 77989979. The next prime is 77990009. The reversal of 77989985 is 58998977.

It is a cyclic number.

It is not a de Polignac number, because 77989985 - 2⁶ = 77989921 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136781 + ... + 137349.

It is an arithmetic number, because the mean of its divisors is an integer number (5950800).

Almost surely, 2^77989985 is an apocalyptic number.

It is an amenable number.

77989985 is a deficient number, since it is larger than the sum of its proper divisors (17222815).

77989985 is a wasteful number, since it uses less digits than its factorization.

77989985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000.

The product of its digits is 11430720, while the sum is 62.

The square root of 77989985 is about 8831.1938604019. The cubic root of 77989985 is about 427.2475807731.

The spelling of 77989985 in words is "seventy-seven million, nine hundred eighty-nine thousand, nine hundred eighty-five".