18791231655 has 32 divisors (see below), whose sum is σ = 34384320000. Its totient is φ = 8584474752.

The previous prime is 18791231651. The next prime is 18791231671. The reversal of 18791231655 is 55613219781.

It is not a de Polignac number, because 18791231655 - 2² = 18791231651 is a prime.

It is a super-2 number, since 2×18791231655² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18791231651) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 97701 + ... + 217089.

It is an arithmetic number, because the mean of its divisors is an integer number (1074510000).

Almost surely, 2^18791231655 is an apocalyptic number.

18791231655 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18791231655 is a deficient number, since it is larger than the sum of its proper divisors (15593088345).

18791231655 is a wasteful number, since it uses less digits than its factorization.

18791231655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120903.

The product of its digits is 453600, while the sum is 48.

The spelling of 18791231655 in words is "eighteen billion, seven hundred ninety-one million, two hundred thirty-one thousand, six hundred fifty-five".