18170986491 has 60 divisors (see below), whose sum is σ = 31448597232. Its totient is φ = 10102343328.

The previous prime is 18170986487. The next prime is 18170986499. The reversal of 18170986491 is 19468907181.

18170986491 is a `hidden beast` number, since 1 + 8 + 1 + 70 + 9 + 86 + 491 = 666.

It is not a de Polignac number, because 18170986491 - 2² = 18170986487 is a prime.

It is a super-2 number, since 2×18170986491² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18170986499) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 788170 + ... + 810896.

Almost surely, 2^18170986491 is an apocalyptic number.

18170986491 is a deficient number, since it is larger than the sum of its proper divisors (13277610741).

18170986491 is an equidigital number, since it uses as much as digits as its factorization.

18170986491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22798 (or 22774 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 54.

The spelling of 18170986491 in words is "eighteen billion, one hundred seventy million, nine hundred eighty-six thousand, four hundred ninety-one".