18912500 has 72 divisors (see below), whose sum is σ = 44294040. Its totient is φ = 7040000.

The previous prime is 18912499. The next prime is 18912527. The reversal of 18912500 is 521981.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 18905104 + 7396 = 4348^2 + 86^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18912500.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 212456 + ... + 212544.

It is an arithmetic number, because the mean of its divisors is an integer number (615195).

Almost surely, 2^18912500 is an apocalyptic number.

18912500 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18912500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22147020).

18912500 is an abundant number, since it is smaller than the sum of its proper divisors (25381540).

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

18912500 is an equidigital number, since it uses as much as digits as its factorization.

18912500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 18912500 is about 4348.8504228129. The cubic root of 18912500 is about 266.4299113910.

The spelling of 18912500 in words is "eighteen million, nine hundred twelve thousand, five hundred".