79780865 has 8 divisors (see below), whose sum is σ = 95844840. Its totient is φ = 63752832.

The previous prime is 79780861. The next prime is 79780871. The reversal of 79780865 is 56808797.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3323329 + 76457536 = 1823^2 + 8744^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 79780865 - 2² = 79780861 is a prime.

It is not an unprimeable number, because it can be changed into a prime (79780861) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3830 + ... + 13199.

It is an arithmetic number, because the mean of its divisors is an integer number (11980605).

Almost surely, 2^79780865 is an apocalyptic number.

It is an amenable number.

79780865 is a deficient number, since it is larger than the sum of its proper divisors (16063975).

79780865 is a wasteful number, since it uses less digits than its factorization.

79780865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17971.

The product of its (nonzero) digits is 846720, while the sum is 50.

The square root of 79780865 is about 8932.0134908093. The cubic root of 79780865 is about 430.4931515307.

The spelling of 79780865 in words is "seventy-nine million, seven hundred eighty thousand, eight hundred sixty-five".