18917868 has 24 divisors (see below), whose sum is σ = 46061568. Its totient is φ = 6031696.

The previous prime is 18917867. The next prime is 18917881. The reversal of 18917868 is 86871981.

It is not an unprimeable number, because it can be changed into a prime (18917861) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 33996 + ... + 34547.

It is an arithmetic number, because the mean of its divisors is an integer number (1919232).

Almost surely, 2^18917868 is an apocalyptic number.

It is an amenable number.

18917868 is an abundant number, since it is smaller than the sum of its proper divisors (27143700).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18917868 is a wasteful number, since it uses less digits than its factorization.

18917868 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68573 (or 68571 counting only the distinct ones).

The product of its digits is 193536, while the sum is 48.

The square root of 18917868 is about 4349.4675536208. The cubic root of 18917868 is about 266.4551162462.

The spelling of 18917868 in words is "eighteen million, nine hundred seventeen thousand, eight hundred sixty-eight".