18233281 has 4 divisors (see below), whose sum is σ = 19890864. Its totient is φ = 16575700.

The previous prime is 18233269. The next prime is 18233287.

18233281 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18233281 - 2⁵ = 18233249 is a prime.

It is a super-2 number, since 2×18233281² = 664905072049922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18233287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 828775 + ... + 828796.

It is an arithmetic number, because the mean of its divisors is an integer number (4972716).

Almost surely, 2^18233281 is an apocalyptic number.

18233281 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18233281 is a deficient number, since it is larger than the sum of its proper divisors (1657583).

18233281 is a wasteful number, since it uses less digits than its factorization.

18233281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1657582.

The product of its digits is 2304, while the sum is 28.

The square root of 18233281 is about 4270.0446133501. The cubic root of 18233281 is about 263.2014484958.

The spelling of 18233281 in words is "eighteen million, two hundred thirty-three thousand, two hundred eighty-one".