78136513065 has 24 divisors (see below), whose sum is σ = 145854825480. Its totient is φ = 38467206144.

The previous prime is 78136513057. The next prime is 78136513079. The reversal of 78136513065 is 56031563187.

78136513065 is a `hidden beast` number, since 78 + 1 + 3 + 6 + 513 + 0 + 65 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 12584128041 + 65552385024 = 112179^2 + 256032^2 .

It is not a de Polignac number, because 78136513065 - 2³ = 78136513057 is a prime.

It is a super-2 number, since 2×78136513065² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 78136513065.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 66782760 + ... + 66783929.

It is an arithmetic number, because the mean of its divisors is an integer number (6077284395).

Almost surely, 2^78136513065 is an apocalyptic number.

It is an amenable number.

78136513065 is a deficient number, since it is larger than the sum of its proper divisors (67718312415).

78136513065 is a wasteful number, since it uses less digits than its factorization.

78136513065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 133566713 (or 133566710 counting only the distinct ones).

The product of its (nonzero) digits is 453600, while the sum is 45.

It can be divided in two parts, 781365 and 13065, that added together give a triangular number (794430 = T₁₂₆₀).

The spelling of 78136513065 in words is "seventy-eight billion, one hundred thirty-six million, five hundred thirteen thousand, sixty-five".