18435990 has 64 divisors (see below), whose sum is σ = 48164544. Its totient is φ = 4497408.

The previous prime is 18435983. The next prime is 18436001. The reversal of 18435990 is 9953481.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 18382 + ... + 19358.

It is an arithmetic number, because the mean of its divisors is an integer number (752571).

Almost surely, 2^18435990 is an apocalyptic number.

18435990 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 18435990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24082272).

18435990 is an abundant number, since it is smaller than the sum of its proper divisors (29728554).

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

18435990 is a wasteful number, since it uses less digits than its factorization.

18435990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1041.

The product of its (nonzero) digits is 38880, while the sum is 39.

The square root of 18435990 is about 4293.7151745313. The cubic root of 18435990 is about 264.1732391407.

The spelling of 18435990 in words is "eighteen million, four hundred thirty-five thousand, nine hundred ninety".