18918433974 has 48 divisors (see below), whose sum is σ = 41627925360. Its totient is φ = 5727532800.

The previous prime is 18918433973. The next prime is 18918433981. The reversal of 18918433974 is 47933481981.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18918433973) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 808114 + ... + 831194.

It is an arithmetic number, because the mean of its divisors is an integer number (867248445).

Almost surely, 2^18918433974 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18918433974, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20813962680).

18918433974 is an abundant number, since it is smaller than the sum of its proper divisors (22709491386).

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

18918433974 is a wasteful number, since it uses less digits than its factorization.

18918433974 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24237 (or 24226 counting only the distinct ones).

The product of its digits is 5225472, while the sum is 57.

The spelling of 18918433974 in words is "eighteen billion, nine hundred eighteen million, four hundred thirty-three thousand, nine hundred seventy-four".