18005590 has 16 divisors (see below), whose sum is σ = 32775840. Its totient is φ = 7120960.

The previous prime is 18005579. The next prime is 18005591. The reversal of 18005590 is 9550081.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18005591) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 9226 + ... + 11005.

It is an arithmetic number, because the mean of its divisors is an integer number (2048490).

Almost surely, 2^18005590 is an apocalyptic number.

18005590 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18005590 is a deficient number, since it is larger than the sum of its proper divisors (14770250).

18005590 is a wasteful number, since it uses less digits than its factorization.

18005590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20327.

The product of its (nonzero) digits is 1800, while the sum is 28.

The square root of 18005590 is about 4243.2994237975. The cubic root of 18005590 is about 262.1012661396.

The spelling of 18005590 in words is "eighteen million, five thousand, five hundred ninety".