18002881 has 24 divisors (see below), whose sum is σ = 21644280. Its totient is φ = 14816256.

The previous prime is 18002851. The next prime is 18002891. The reversal of 18002881 is 18820081.

It can be written as a sum of positive squares in 12 ways, for example, as 705600 + 17297281 = 840^2 + 4159^2 .

It is not a de Polignac number, because 18002881 - 2⁵ = 18002849 is a prime.

It is a super-2 number, since 2×18002881² = 648207448600322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18002851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 339651 + ... + 339703.

It is an arithmetic number, because the mean of its divisors is an integer number (901845).

Almost surely, 2^18002881 is an apocalyptic number.

It is an amenable number.

18002881 is a deficient number, since it is larger than the sum of its proper divisors (3641399).

18002881 is a wasteful number, since it uses less digits than its factorization.

18002881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165 (or 112 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 28.

The square root of 18002881 is about 4242.9802026406. The cubic root of 18002881 is about 262.0881208156.

The spelling of 18002881 in words is "eighteen million, two thousand, eight hundred eighty-one".