18555538240 has 28 divisors (see below), whose sum is σ = 44185376196. Its totient is φ = 7422215168.

The previous prime is 18555538231. The next prime is 18555538241. The reversal of 18555538240 is 4283555581.

It can be written as a sum of positive squares in 2 ways, for example, as 7895388736 + 10660149504 = 88856^2 + 103248^2 .

It is a super-2 number, since 2×18555538240² (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 (18555538241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28992709 + ... + 28993348.

Almost surely, 2^18555538240 is an apocalyptic number.

18555538240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18555538240 is an abundant number, since it is smaller than the sum of its proper divisors (25629837956).

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

18555538240 is an equidigital number, since it uses as much as digits as its factorization.

18555538240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57986074 (or 57986064 counting only the distinct ones).

The product of its (nonzero) digits is 960000, while the sum is 46.

The spelling of 18555538240 in words is "eighteen billion, five hundred fifty-five million, five hundred thirty-eight thousand, two hundred forty".