78179512891 has 8 divisors (see below), whose sum is σ = 78982847840. Its totient is φ = 77377030272.

The previous prime is 78179512847. The next prime is 78179512903. The reversal of 78179512891 is 19821597187.

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

It is a cyclic number.

It is not a de Polignac number, because 78179512891 - 2²⁵ = 78145958459 is a prime.

It is a super-2 number, since 2×78179512891² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78179512291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27870 + ... + 396403.

It is an arithmetic number, because the mean of its divisors is an integer number (9872855980).

Almost surely, 2^78179512891 is an apocalyptic number.

78179512891 is a deficient number, since it is larger than the sum of its proper divisors (803334949).

78179512891 is a wasteful number, since it uses less digits than its factorization.

78179512891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 426165.

The product of its digits is 2540160, while the sum is 58.

The spelling of 78179512891 in words is "seventy-eight billion, one hundred seventy-nine million, five hundred twelve thousand, eight hundred ninety-one".