18912840 has 128 divisors (see below), whose sum is σ = 61378560. Its totient is φ = 4644864.

The previous prime is 18912811. The next prime is 18912841. The reversal of 18912840 is 4821981.

It is not an unprimeable number, because it can be changed into a prime (18912841) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 148857 + ... + 148983.

It is an arithmetic number, because the mean of its divisors is an integer number (479520).

Almost surely, 2^18912840 is an apocalyptic number.

18912840 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 18912840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30689280).

18912840 is an abundant number, since it is smaller than the sum of its proper divisors (42465720).

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

18912840 is a wasteful number, since it uses less digits than its factorization.

18912840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231 (or 227 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 33.

The square root of 18912840 is about 4348.8895134275. The cubic root of 18912840 is about 266.4315079652.

The spelling of 18912840 in words is "eighteen million, nine hundred twelve thousand, eight hundred forty".