77891365 has 16 divisors (see below), whose sum is σ = 100331568. Its totient is φ = 57839616.

The previous prime is 77891357. The next prime is 77891383. The reversal of 77891365 is 56319877.

It can be written as a sum of positive squares in 8 ways, for example, as 16394401 + 61496964 = 4049^2 + 7842^2 .

It is a cyclic number.

It is not a de Polignac number, because 77891365 - 2³ = 77891357 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 72 + ... + 12481.

It is an arithmetic number, because the mean of its divisors is an integer number (6270723).

Almost surely, 2^77891365 is an apocalyptic number.

It is an amenable number.

77891365 is a deficient number, since it is larger than the sum of its proper divisors (22440203).

77891365 is a wasteful number, since it uses less digits than its factorization.

77891365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12648.

The product of its digits is 317520, while the sum is 46.

The square root of 77891365 is about 8825.6084776065. The cubic root of 77891365 is about 427.0674169176.

The spelling of 77891365 in words is "seventy-seven million, eight hundred ninety-one thousand, three hundred sixty-five".