77768765 has 4 divisors (see below), whose sum is σ = 93322524. Its totient is φ = 62215008.

The previous prime is 77768741. The next prime is 77768809. The reversal of 77768765 is 56786777.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56786777 = 5531 ⋅10267.

It can be written as a sum of positive squares in 2 ways, for example, as 57365476 + 20403289 = 7574^2 + 4517^2 .

It is a cyclic number.

It is not a de Polignac number, because 77768765 - 2⁶ = 77768701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7776872 + ... + 7776881.

It is an arithmetic number, because the mean of its divisors is an integer number (23330631).

Almost surely, 2^77768765 is an apocalyptic number.

It is an amenable number.

77768765 is a deficient number, since it is larger than the sum of its proper divisors (15553759).

77768765 is a wasteful number, since it uses less digits than its factorization.

77768765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15553758.

The product of its digits is 3457440, while the sum is 53.

The square root of 77768765 is about 8818.6600456078. The cubic root of 77768765 is about 426.8432330607.

The spelling of 77768765 in words is "seventy-seven million, seven hundred sixty-eight thousand, seven hundred sixty-five".