18481890 has 128 divisors (see below), whose sum is σ = 55738368. Its totient is φ = 3824640.

The previous prime is 18481871. The next prime is 18481891. The reversal of 18481890 is 9818481.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (18481891) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 110587 + ... + 110753.

It is an arithmetic number, because the mean of its divisors is an integer number (435456).

Almost surely, 2^18481890 is an apocalyptic number.

18481890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18481890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27869184).

18481890 is an abundant number, since it is smaller than the sum of its proper divisors (37256478).

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

18481890 is a wasteful number, since it uses less digits than its factorization.

18481890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 232.

The product of its (nonzero) digits is 18432, while the sum is 39.

The square root of 18481890 is about 4299.0568733154. The cubic root of 18481890 is about 264.3922944160.

The spelling of 18481890 in words is "eighteen million, four hundred eighty-one thousand, eight hundred ninety".