18055881 has 12 divisors (see below), whose sum is σ = 26573508. Its totient is φ = 11809824.

The previous prime is 18055879. The next prime is 18055901. The reversal of 18055881 is 18855081.

It can be written as a sum of positive squares in 2 ways, for example, as 4769856 + 13286025 = 2184^2 + 3645^2 .

It is not a de Polignac number, because 18055881 - 2¹ = 18055879 is a prime.

It is a super-2 number, since 2×18055881² = 652029677372322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18055801) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18450 + ... + 19403.

It is an arithmetic number, because the mean of its divisors is an integer number (2214459).

Almost surely, 2^18055881 is an apocalyptic number.

It is an amenable number.

18055881 is a deficient number, since it is larger than the sum of its proper divisors (8517627).

18055881 is a wasteful number, since it uses less digits than its factorization.

18055881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37912 (or 37909 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 36.

The square root of 18055881 is about 4249.2212227654. The cubic root of 18055881 is about 262.3450623092.

The spelling of 18055881 in words is "eighteen million, fifty-five thousand, eight hundred eighty-one".