18418881 has 16 divisors (see below), whose sum is σ = 27095040. Its totient is φ = 11057280.

The previous prime is 18418861. The next prime is 18418927. The reversal of 18418881 is 18881481.

It is not a de Polignac number, because 18418881 - 2⁹ = 18418369 is a prime.

It is a super-2 number, since 2×18418881² = 678510354584322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18418831) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4161 + ... + 7358.

It is an arithmetic number, because the mean of its divisors is an integer number (1693440).

Almost surely, 2^18418881 is an apocalyptic number.

It is an amenable number.

18418881 is a deficient number, since it is larger than the sum of its proper divisors (8676159).

18418881 is a wasteful number, since it uses less digits than its factorization.

18418881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11576.

The product of its digits is 16384, while the sum is 39.

The square root of 18418881 is about 4291.7223815154. The cubic root of 18418881 is about 264.0914943432.

The spelling of 18418881 in words is "eighteen million, four hundred eighteen thousand, eight hundred eighty-one".