77120665 has 4 divisors (see below), whose sum is σ = 92544804. Its totient is φ = 61696528.

The previous prime is 77120663. The next prime is 77120699. The reversal of 77120665 is 56602177.

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 46826649 + 30294016 = 6843^2 + 5504^2 .

It is a cyclic number.

It is not a de Polignac number, because 77120665 - 2¹ = 77120663 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 77120665.

It is not an unprimeable number, because it can be changed into a prime (77120663) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7712062 + ... + 7712071.

It is an arithmetic number, because the mean of its divisors is an integer number (23136201).

Almost surely, 2^77120665 is an apocalyptic number.

It is an amenable number.

77120665 is a deficient number, since it is larger than the sum of its proper divisors (15424139).

77120665 is a wasteful number, since it uses less digits than its factorization.

77120665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15424138.

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 77120665 is about 8781.8372223584. The cubic root of 77120665 is about 425.6541989394.

The spelling of 77120665 in words is "seventy-seven million, one hundred twenty thousand, six hundred sixty-five".