18000181836 has 144 divisors (see below), whose sum is σ = 56180464704. Its totient is φ = 4732051968.

The previous prime is 18000181831. The next prime is 18000181861. The reversal of 18000181836 is 63818100081.

It is a super-2 number, since 2×18000181836² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 18000181836.

It is not an unprimeable number, because it can be changed into a prime (18000181831) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1029826 + ... + 1047158.

It is an arithmetic number, because the mean of its divisors is an integer number (390142116).

Almost surely, 2^18000181836 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18000181836, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28090232352).

18000181836 is an abundant number, since it is smaller than the sum of its proper divisors (38180282868).

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

18000181836 is a wasteful number, since it uses less digits than its factorization.

18000181836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17680 (or 17675 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The spelling of 18000181836 in words is "eighteen billion, one hundred eighty-one thousand, eight hundred thirty-six".