18185733220 has 12 divisors (see below), whose sum is σ = 38190039804. Its totient is φ = 7274293280.

The previous prime is 18185733197. The next prime is 18185733259. The reversal of 18185733220 is 2233758181.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 4984642404 + 13201090816 = 70602^2 + 114896^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454643311 + ... + 454643350.

It is an arithmetic number, because the mean of its divisors is an integer number (3182503317).

Almost surely, 2^18185733220 is an apocalyptic number.

18185733220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18185733220 is an abundant number, since it is smaller than the sum of its proper divisors (20004306584).

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

18185733220 is a wasteful number, since it uses less digits than its factorization.

18185733220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909286670 (or 909286668 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 40.

The spelling of 18185733220 in words is "eighteen billion, one hundred eighty-five million, seven hundred thirty-three thousand, two hundred twenty".