78728684231 has 4 divisors (see below), whose sum is σ = 78736368600. Its totient is φ = 78720999864.

The previous prime is 78728684161. The next prime is 78728684267. The reversal of 78728684231 is 13248682787.

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

It is a cyclic number.

It is not a de Polignac number, because 78728684231 - 2²⁶ = 78661575367 is a prime.

It is a super-2 number, since 2×78728684231² (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 (78728684131) 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, 3826796 + ... + 3847313.

It is an arithmetic number, because the mean of its divisors is an integer number (19684092150).

Almost surely, 2^78728684231 is an apocalyptic number.

78728684231 is a deficient number, since it is larger than the sum of its proper divisors (7684369).

78728684231 is a wasteful number, since it uses less digits than its factorization.

78728684231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7684368.

The product of its digits is 7225344, while the sum is 56.

The spelling of 78728684231 in words is "seventy-eight billion, seven hundred twenty-eight million, six hundred eighty-four thousand, two hundred thirty-one".