18533281956 has 96 divisors (see below), whose sum is σ = 51504230400. Its totient is φ = 5182504992.

The previous prime is 18533281933. The next prime is 18533281997. The reversal of 18533281956 is 65918233581.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 18533281899 and 18533281908.

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, 145551 + ... + 241353.

It is an arithmetic number, because the mean of its divisors is an integer number (536502400).

Almost surely, 2^18533281956 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 18533281956, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25752115200).

18533281956 is an abundant number, since it is smaller than the sum of its proper divisors (32970948444).

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

18533281956 is a wasteful number, since it uses less digits than its factorization.

18533281956 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95878 (or 95862 counting only the distinct ones).

The product of its digits is 1555200, while the sum is 51.

The spelling of 18533281956 in words is "eighteen billion, five hundred thirty-three million, two hundred eighty-one thousand, nine hundred fifty-six".