18881994 has 16 divisors (see below), whose sum is σ = 37977120. Its totient is φ = 6258480.

The previous prime is 18881983. The next prime is 18881999. The reversal of 18881994 is 49918881.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18881999) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7717 + ... + 9864.

It is an arithmetic number, because the mean of its divisors is an integer number (2373570).

Almost surely, 2^18881994 is an apocalyptic number.

18881994 is an abundant number, since it is smaller than the sum of its proper divisors (19095126).

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

18881994 is a wasteful number, since it uses less digits than its factorization.

18881994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17765.

The product of its digits is 165888, while the sum is 48.

The square root of 18881994 is about 4345.3416436455. The cubic root of 18881994 is about 266.2865831722.

The spelling of 18881994 in words is "eighteen million, eight hundred eighty-one thousand, nine hundred ninety-four".