18801993438 has 48 divisors (see below), whose sum is σ = 45404208720. Its totient is φ = 5588206848.

The previous prime is 18801993437. The next prime is 18801993449. The reversal of 18801993438 is 83439910881.

18801993438 is a `hidden beast` number, since 18 + 8 + 0 + 199 + 3 + 438 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18801993433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1611145 + ... + 1622772.

It is an arithmetic number, because the mean of its divisors is an integer number (945921015).

Almost surely, 2^18801993438 is an apocalyptic number.

18801993438 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18801993438 is an abundant number, since it is smaller than the sum of its proper divisors (26602215282).

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

18801993438 is a wasteful number, since it uses less digits than its factorization.

18801993438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3233961 (or 3233958 counting only the distinct ones).

The product of its (nonzero) digits is 1492992, while the sum is 54.

The spelling of 18801993438 in words is "eighteen billion, eight hundred one million, nine hundred ninety-three thousand, four hundred thirty-eight".