78165544973 has 4 divisors (see below), whose sum is σ = 78166632060. Its totient is φ = 78164457888.

The previous prime is 78165544967. The next prime is 78165544993. The reversal of 78165544973 is 37944556187.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15296000329 + 62869544644 = 123677^2 + 250738^2 .

It is a cyclic number.

It is not a de Polignac number, because 78165544973 - 2²⁴ = 78148767757 is a prime.

It is a super-2 number, since 2×78165544973² (a number of 23 digits) 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 (78165544903) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 427418 + ... + 582251.

It is an arithmetic number, because the mean of its divisors is an integer number (19541658015).

Almost surely, 2^78165544973 is an apocalyptic number.

It is an amenable number.

78165544973 is a deficient number, since it is larger than the sum of its proper divisors (1087087).

78165544973 is a wasteful number, since it uses less digits than its factorization.

78165544973 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1087086.

The product of its digits is 25401600, while the sum is 59.

It can be divided in two parts, 781655 and 44973, that added together give a palindrome (826628).

The spelling of 78165544973 in words is "seventy-eight billion, one hundred sixty-five million, five hundred forty-four thousand, nine hundred seventy-three".