18890231 has 4 divisors (see below), whose sum is σ = 18924000. Its totient is φ = 18856464.

The previous prime is 18890203. The next prime is 18890257. The reversal of 18890231 is 13209881.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18890231 - 2⁶ = 18890167 is a prime.

It is a super-2 number, since 2×18890231² = 713681654466722, 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 (18895231) 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, 16031 + ... + 17168.

It is an arithmetic number, because the mean of its divisors is an integer number (4731000).

Almost surely, 2^18890231 is an apocalyptic number.

18890231 is a deficient number, since it is larger than the sum of its proper divisors (33769).

18890231 is an equidigital number, since it uses as much as digits as its factorization.

18890231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33768.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 18890231 is about 4346.2893368942. The cubic root of 18890231 is about 266.3252987816.

The spelling of 18890231 in words is "eighteen million, eight hundred ninety thousand, two hundred thirty-one".