18945090 has 80 divisors (see below), whose sum is σ = 53665920. Its totient is φ = 4782240.

The previous prime is 18945083. The next prime is 18945103. The reversal of 18945090 is 9054981.

18945090 is a nontrivial binomial coefficient, being equal to C(6156, 2).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is an alternating number because its digits alternate between odd and even.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 14775 + ... + 16005.

It is an arithmetic number, because the mean of its divisors is an integer number (670824).

Almost surely, 2^18945090 is an apocalyptic number.

18945090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18945090 is the 6155-th triangular number and also the 3078-th hexagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18945090, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26832960).

18945090 is an abundant number, since it is smaller than the sum of its proper divisors (34720830).

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

18945090 is a wasteful number, since it uses less digits than its factorization.

18945090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1269 (or 1260 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 18945090 is about 4352.5957772345. The cubic root of 18945090 is about 266.5828608177.

The spelling of 18945090 in words is "eighteen million, nine hundred forty-five thousand, ninety".