78818111681 has 8 divisors (see below), whose sum is σ = 79212989184. Its totient is φ = 78423604560.

The previous prime is 78818111629. The next prime is 78818111689. The reversal of 78818111681 is 18611181887.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78818111681 is a prime.

It is a super-2 number, since 2×78818111681² (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 (78818111689) 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, 339095 + ... + 522131.

It is an arithmetic number, because the mean of its divisors is an integer number (9901623648).

Almost surely, 2^78818111681 is an apocalyptic number.

It is an amenable number.

78818111681 is a deficient number, since it is larger than the sum of its proper divisors (394877503).

78818111681 is a wasteful number, since it uses less digits than its factorization.

78818111681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185191.

The product of its digits is 172032, while the sum is 50.

The spelling of 78818111681 in words is "seventy-eight billion, eight hundred eighteen million, one hundred eleven thousand, six hundred eighty-one".