18747988 has 36 divisors (see below), whose sum is σ = 39113172. Its totient is φ = 7835520.

The previous prime is 18747977. The next prime is 18748021. The reversal of 18747988 is 88974781.

It can be written as a sum of positive squares in 2 ways, for example, as 3161284 + 15586704 = 1778^2 + 3948^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6870 + ... + 9202.

It is an arithmetic number, because the mean of its divisors is an integer number (1086477).

Almost surely, 2^18747988 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18747988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19556586).

18747988 is an abundant number, since it is smaller than the sum of its proper divisors (20365184).

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

18747988 is a wasteful number, since it uses less digits than its factorization.

18747988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2392 (or 2383 counting only the distinct ones).

The product of its digits is 903168, while the sum is 52.

The square root of 18747988 is about 4329.8946869410. The cubic root of 18747988 is about 265.6551394267.

The spelling of 18747988 in words is "eighteen million, seven hundred forty-seven thousand, nine hundred eighty-eight".