78816172031 has 2 divisors, whose sum is σ = 78816172032. Its totient is φ = 78816172030.

The previous prime is 78816171979. The next prime is 78816172033. The reversal of 78816172031 is 13027161887.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 78816172031 - 2²⁶ = 78749063167 is a prime.

It is a super-2 number, since 2×78816172031² (a number of 23 digits) contains 22 as substring.

Together with 78816172033, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78816172033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39408086015 + 39408086016.

It is an arithmetic number, because the mean of its divisors is an integer number (39408086016).

Almost surely, 2^78816172031 is an apocalyptic number.

78816172031 is a deficient number, since it is larger than the sum of its proper divisors (1).

78816172031 is an equidigital number, since it uses as much as digits as its factorization.

78816172031 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 112896, while the sum is 44.

The spelling of 78816172031 in words is "seventy-eight billion, eight hundred sixteen million, one hundred seventy-two thousand, thirty-one".