78685765 has 8 divisors (see below), whose sum is σ = 96726168. Its totient is φ = 61413120.

The previous prime is 78685759. The next prime is 78685769. The reversal of 78685765 is 56758687.

It can be written as a sum of positive squares in 4 ways, for example, as 4605316 + 74080449 = 2146^2 + 8607^2 .

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

It is not a de Polignac number, because 78685765 - 2⁷ = 78685637 is a prime.

It is a super-2 number, since 2×78685765² = 12382899227270450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78685769) 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 7 ways as a sum of consecutive naturals, for example, 191712 + ... + 192121.

It is an arithmetic number, because the mean of its divisors is an integer number (12090771).

Almost surely, 2^78685765 is an apocalyptic number.

It is an amenable number.

78685765 is a deficient number, since it is larger than the sum of its proper divisors (18040403).

78685765 is a wasteful number, since it uses less digits than its factorization.

78685765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383879.

The product of its digits is 2822400, while the sum is 52.

The square root of 78685765 is about 8870.4997040753. The cubic root of 78685765 is about 428.5143701551.

The spelling of 78685765 in words is "seventy-eight million, six hundred eighty-five thousand, seven hundred sixty-five".