78186397105 has 4 divisors (see below), whose sum is σ = 93823676532. Its totient is φ = 62549117680.

The previous prime is 78186397099. The next prime is 78186397141. The reversal of 78186397105 is 50179368187.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 50179368187 = 13 ⋅3859951399.

It can be written as a sum of positive squares in 2 ways, for example, as 40006800289 + 38179596816 = 200017^2 + 195396^2 .

It is not a de Polignac number, because 78186397105 - 2³ = 78186397097 is a prime.

It is a super-2 number, since 2×78186397105² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7818639706 + ... + 7818639715.

It is an arithmetic number, because the mean of its divisors is an integer number (23455919133).

Almost surely, 2^78186397105 is an apocalyptic number.

It is an amenable number.

78186397105 is a deficient number, since it is larger than the sum of its proper divisors (15637279427).

78186397105 is a wasteful number, since it uses less digits than its factorization.

78186397105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15637279426.

The product of its (nonzero) digits is 2540160, while the sum is 55.

The spelling of 78186397105 in words is "seventy-eight billion, one hundred eighty-six million, three hundred ninety-seven thousand, one hundred five".