18188890 has 16 divisors (see below), whose sum is σ = 34463520. Its totient is φ = 6892560.

The previous prime is 18188879. The next prime is 18188893. The reversal of 18188890 is 9888181.

It is not an unprimeable number, because it can be changed into a prime (18188893) by changing a digit.

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, 47676 + ... + 48055.

It is an arithmetic number, because the mean of its divisors is an integer number (2153970).

Almost surely, 2^18188890 is an apocalyptic number.

18188890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18188890 is a deficient number, since it is larger than the sum of its proper divisors (16274630).

18188890 is a wasteful number, since it uses less digits than its factorization.

18188890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95757.

The product of its (nonzero) digits is 36864, while the sum is 43.

The square root of 18188890 is about 4264.8434906805. The cubic root of 18188890 is about 262.9876769467.

The spelling of 18188890 in words is "eighteen million, one hundred eighty-eight thousand, eight hundred ninety".