77664865 has 16 divisors (see below), whose sum is σ = 95795280. Its totient is φ = 60410880.

The previous prime is 77664863. The next prime is 77664869. The reversal of 77664865 is 56846677.

It can be written as a sum of positive squares in 8 ways, for example, as 944784 + 76720081 = 972^2 + 8759^2 .

It is not a de Polignac number, because 77664865 - 2¹ = 77664863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77664863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 93271 + ... + 94099.

It is an arithmetic number, because the mean of its divisors is an integer number (5987205).

Almost surely, 2^77664865 is an apocalyptic number.

It is an amenable number.

77664865 is a deficient number, since it is larger than the sum of its proper divisors (18130415).

77664865 is a wasteful number, since it uses less digits than its factorization.

77664865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1332.

The product of its digits is 1693440, while the sum is 49.

The square root of 77664865 is about 8812.7671590710. The cubic root of 77664865 is about 426.6530591228.

The spelling of 77664865 in words is "seventy-seven million, six hundred sixty-four thousand, eight hundred sixty-five".