78165405663 has 16 divisors (see below), whose sum is σ = 110365443936. Its totient is φ = 49038612480.

The previous prime is 78165405641. The next prime is 78165405667. The reversal of 78165405663 is 36650456187.

It is not a de Polignac number, because 78165405663 - 2²⁰ = 78164357087 is a prime.

It is a super-2 number, since 2×78165405663² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78165405667) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 315543 + ... + 505863.

It is an arithmetic number, because the mean of its divisors is an integer number (6897840246).

Almost surely, 2^78165405663 is an apocalyptic number.

78165405663 is a deficient number, since it is larger than the sum of its proper divisors (32200038273).

78165405663 is a wasteful number, since it uses less digits than its factorization.

78165405663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 198394.

The product of its (nonzero) digits is 3628800, while the sum is 51.

The spelling of 78165405663 in words is "seventy-eight billion, one hundred sixty-five million, four hundred five thousand, six hundred sixty-three".