18531868 has 12 divisors (see below), whose sum is σ = 32537232. Its totient is φ = 9235520.

The previous prime is 18531829. The next prime is 18531881. The reversal of 18531868 is 86813581.

It is a self number, because there is not a number n which added to its sum of digits gives 18531868.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6205 + ... + 8692.

It is an arithmetic number, because the mean of its divisors is an integer number (2711436).

Almost surely, 2^18531868 is an apocalyptic number.

It is an amenable number.

18531868 is a deficient number, since it is larger than the sum of its proper divisors (14005364).

18531868 is a wasteful number, since it uses less digits than its factorization.

18531868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15212 (or 15210 counting only the distinct ones).

The product of its digits is 46080, while the sum is 40.

The square root of 18531868 is about 4304.8656192731. The cubic root of 18531868 is about 264.6303996677.

It can be divided in two parts, 1853 and 1868, that added together give a square (3721 = 61²).

The spelling of 18531868 in words is "eighteen million, five hundred thirty-one thousand, eight hundred sixty-eight".