18312133 has 6 divisors (see below), whose sum is σ = 21301926. Its totient is φ = 15696072.

The previous prime is 18312131. The next prime is 18312167. The reversal of 18312133 is 33121381.

It can be written as a sum of positive squares in only one way, i.e., 15697444 + 2614689 = 3962^2 + 1617^2 .

It is not a de Polignac number, because 18312133 - 2¹ = 18312131 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18312131) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 186810 + ... + 186907.

It is an arithmetic number, because the mean of its divisors is an integer number (3550321).

Almost surely, 2^18312133 is an apocalyptic number.

It is an amenable number.

18312133 is a deficient number, since it is larger than the sum of its proper divisors (2989793).

18312133 is an equidigital number, since it uses as much as digits as its factorization.

18312133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 373731 (or 373724 counting only the distinct ones).

The product of its digits is 432, while the sum is 22.

The square root of 18312133 is about 4279.2678112032. The cubic root of 18312133 is about 263.5803182237.

The spelling of 18312133 in words is "eighteen million, three hundred twelve thousand, one hundred thirty-three".