18087890 has 16 divisors (see below), whose sum is σ = 33974208. Its totient is φ = 6920496.

The previous prime is 18087887. The next prime is 18087899. The reversal of 18087890 is 9878081.

It is not an unprimeable number, because it can be changed into a prime (18087899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39092 + ... + 39551.

It is an arithmetic number, because the mean of its divisors is an integer number (2123388).

Almost surely, 2^18087890 is an apocalyptic number.

18087890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18087890 is a deficient number, since it is larger than the sum of its proper divisors (15886318).

18087890 is a wasteful number, since it uses less digits than its factorization.

18087890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78673.

The product of its (nonzero) digits is 32256, while the sum is 41.

The square root of 18087890 is about 4252.9860098524. The cubic root of 18087890 is about 262.4999969766.

The spelling of 18087890 in words is "eighteen million, eighty-seven thousand, eight hundred ninety".