18099890 has 16 divisors (see below), whose sum is σ = 32647320. Its totient is φ = 7224960.

The previous prime is 18099869. The next prime is 18099929. The reversal of 18099890 is 9899081.

It can be written as a sum of positive squares in 4 ways, for example, as 6964321 + 11135569 = 2639^2 + 3337^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4100 + ... + 7280.

Almost surely, 2^18099890 is an apocalyptic number.

18099890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18099890 is a deficient number, since it is larger than the sum of its proper divisors (14547430).

18099890 is a wasteful number, since it uses less digits than its factorization.

18099890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3757.

The product of its (nonzero) digits is 46656, while the sum is 44.

The square root of 18099890 is about 4254.3965494533. The cubic root of 18099890 is about 262.5580340320.

The spelling of 18099890 in words is "eighteen million, ninety-nine thousand, eight hundred ninety".