77780765 has 16 divisors (see below), whose sum is σ = 96412800. Its totient is φ = 60201792.

The previous prime is 77780753. The next prime is 77780777. The reversal of 77780765 is 56708777.

It is an interprime number because it is at equal distance from previous prime (77780753) and next prime (77780777).

It is a cyclic number.

It is not a de Polignac number, because 77780765 - 2¹² = 77776669 is a prime.

It is a congruent number.

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, 21776 + ... + 25094.

It is an arithmetic number, because the mean of its divisors is an integer number (6025800).

Almost surely, 2^77780765 is an apocalyptic number.

It is an amenable number.

77780765 is a deficient number, since it is larger than the sum of its proper divisors (18632035).

77780765 is a wasteful number, since it uses less digits than its factorization.

77780765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3476.

The product of its (nonzero) digits is 576240, while the sum is 47.

The square root of 77780765 is about 8819.3403948368. The cubic root of 77780765 is about 426.8651864133.

The spelling of 77780765 in words is "seventy-seven million, seven hundred eighty thousand, seven hundred sixty-five".