18917112656 has 40 divisors (see below), whose sum is σ = 39699516360. Its totient is φ = 8680490496.

The previous prime is 18917112649. The next prime is 18917112659. The reversal of 18917112656 is 65621171981.

It can be written as a sum of positive squares in 4 ways, for example, as 6493781056 + 12423331600 = 80584^2 + 111460^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18917112656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18917112659) 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, 226871 + ... + 298838.

It is an arithmetic number, because the mean of its divisors is an integer number (992487909).

Almost surely, 2^18917112656 is an apocalyptic number.

18917112656 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

18917112656 is an abundant number, since it is smaller than the sum of its proper divisors (20782403704).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18917112656 is a wasteful number, since it uses less digits than its factorization.

18917112656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525903 (or 525897 counting only the distinct ones).

The product of its digits is 181440, while the sum is 47.

The spelling of 18917112656 in words is "eighteen billion, nine hundred seventeen million, one hundred twelve thousand, six hundred fifty-six".