18757818 has 40 divisors (see below), whose sum is σ = 42536340. Its totient is φ = 6177600.

The previous prime is 18757801. The next prime is 18757819. The reversal of 18757818 is 81875781.

It can be written as a sum of positive squares in 2 ways, for example, as 13816089 + 4941729 = 3717^2 + 2223^2 .

It is a super-2 number, since 2×18757818² = 703711472242248, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18757819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13768 + ... + 15068.

Almost surely, 2^18757818 is an apocalyptic number.

18757818 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 18757818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21268170).

18757818 is an abundant number, since it is smaller than the sum of its proper divisors (23778522).

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

18757818 is a wasteful number, since it uses less digits than its factorization.

18757818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404 (or 1395 counting only the distinct ones).

The product of its digits is 125440, while the sum is 45.

The square root of 18757818 is about 4331.0296697206. The cubic root of 18757818 is about 265.7015610080.

The spelling of 18757818 in words is "eighteen million, seven hundred fifty-seven thousand, eight hundred eighteen".