18668533 has 12 divisors (see below), whose sum is σ = 21361060. Its totient is φ = 16215552.

The previous prime is 18668513. The next prime is 18668549. The reversal of 18668533 is 33586681.

It can be written as a sum of positive squares in 6 ways, for example, as 66564 + 18601969 = 258^2 + 4313^2 .

It is not a de Polignac number, because 18668533 - 2⁹ = 18668021 is a prime.

It is a hoax number, since the sum of its digits (40) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18668513) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1273 + ... + 6241.

Almost surely, 2^18668533 is an apocalyptic number.

18668533 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18668533 is a deficient number, since it is larger than the sum of its proper divisors (2692527).

18668533 is a wasteful number, since it uses less digits than its factorization.

18668533 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5016 (or 4999 counting only the distinct ones).

The product of its digits is 103680, while the sum is 40.

The square root of 18668533 is about 4320.7097796543. The cubic root of 18668533 is about 265.2793210022.

The spelling of 18668533 in words is "eighteen million, six hundred sixty-eight thousand, five hundred thirty-three".