18507690 has 80 divisors (see below), whose sum is σ = 50608008. Its totient is φ = 4852224.

The previous prime is 18507661. The next prime is 18507701. The reversal of 18507690 is 9670581.

It can be written as a sum of positive squares in 4 ways, for example, as 9308601 + 9199089 = 3051^2 + 3033^2 .

It is a super-2 number, since 2×18507690² = 685069178272200, which contains 22 as substring.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 58974 + ... + 59286.

Almost surely, 2^18507690 is an apocalyptic number.

18507690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18507690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25304004).

18507690 is an abundant number, since it is smaller than the sum of its proper divisors (32100318).

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

18507690 is a wasteful number, since it uses less digits than its factorization.

18507690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405 (or 396 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 36.

The square root of 18507690 is about 4302.0564849848. The cubic root of 18507690 is about 264.5152643352.

The spelling of 18507690 in words is "eighteen million, five hundred seven thousand, six hundred ninety".