18021233 has 2 divisors, whose sum is σ = 18021234. Its totient is φ = 18021232.

The previous prime is 18021217. The next prime is 18021239. The reversal of 18021233 is 33212081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17783089 + 238144 = 4217^2 + 488^2 .

It is a cyclic number.

It is not a de Polignac number, because 18021233 - 2⁴ = 18021217 is a prime.

It is a Chen prime.

It is equal to p_1152614 and since 18021233 and 1152614 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (18021239) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9010616 + 9010617.

It is an arithmetic number, because the mean of its divisors is an integer number (9010617).

Almost surely, 2^18021233 is an apocalyptic number.

It is an amenable number.

18021233 is a deficient number, since it is larger than the sum of its proper divisors (1).

18021233 is an equidigital number, since it uses as much as digits as its factorization.

18021233 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 18021233 is about 4245.1422826567. The cubic root of 18021233 is about 262.1771474506.

The spelling of 18021233 in words is "eighteen million, twenty-one thousand, two hundred thirty-three".