18309011556 has 96 divisors (see below), whose sum is σ = 48416256000. Its totient is φ = 5334825600.

The previous prime is 18309011527. The next prime is 18309011569. The reversal of 18309011556 is 65511090381.

It is a super-2 number, since 2×18309011556² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 628195 + ... + 656693.

It is an arithmetic number, because the mean of its divisors is an integer number (504336000).

Almost surely, 2^18309011556 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 18309011556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24208128000).

18309011556 is an abundant number, since it is smaller than the sum of its proper divisors (30107244444).

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

18309011556 is a wasteful number, since it uses less digits than its factorization.

18309011556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28705 (or 28703 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 39.

The spelling of 18309011556 in words is "eighteen billion, three hundred nine million, eleven thousand, five hundred fifty-six".