18668894 has 4 divisors (see below), whose sum is σ = 28003344. Its totient is φ = 9334446.

The previous prime is 18668861. The next prime is 18668921. The reversal of 18668894 is 49886681.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49886681 = 13 ⋅3837437.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4667222 + ... + 4667225.

It is an arithmetic number, because the mean of its divisors is an integer number (7000836).

Almost surely, 2^18668894 is an apocalyptic number.

18668894 is a deficient number, since it is larger than the sum of its proper divisors (9334450).

18668894 is an equidigital number, since it uses as much as digits as its factorization.

18668894 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9334449.

The product of its digits is 663552, while the sum is 50.

The square root of 18668894 is about 4320.7515549960. The cubic root of 18668894 is about 265.2810309244.

The spelling of 18668894 in words is "eighteen million, six hundred sixty-eight thousand, eight hundred ninety-four".