18774018 has 60 divisors (see below), whose sum is σ = 44799282. Its totient is φ = 5875200.

The previous prime is 18774011. The next prime is 18774043. The reversal of 18774018 is 81047781.

It can be written as a sum of positive squares in 3 ways, for example, as 17665209 + 1108809 = 4203^2 + 1053^2 .

It is not an unprimeable number, because it can be changed into a prime (18774011) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 46618 + ... + 47018.

Almost surely, 2^18774018 is an apocalyptic number.

18774018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18774018, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22399641).

18774018 is an abundant number, since it is smaller than the sum of its proper divisors (26025264).

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

18774018 is a wasteful number, since it uses less digits than its factorization.

18774018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 449 (or 423 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 18774018 is about 4332.8994911029. The cubic root of 18774018 is about 265.7780291548.

The spelling of 18774018 in words is "eighteen million, seven hundred seventy-four thousand, eighteen".