18180998 has 16 divisors (see below), whose sum is σ = 29816640. Its totient is φ = 8245800.

The previous prime is 18180991. The next prime is 18181013. The reversal of 18180998 is 89908181.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18180991) 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, 17333 + ... + 18351.

It is an arithmetic number, because the mean of its divisors is an integer number (1863540).

Almost surely, 2^18180998 is an apocalyptic number.

18180998 is a deficient number, since it is larger than the sum of its proper divisors (11635642).

18180998 is a wasteful number, since it uses less digits than its factorization.

18180998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1843.

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 18180998 is about 4263.9181511844. The cubic root of 18180998 is about 262.9496354280.

The spelling of 18180998 in words is "eighteen million, one hundred eighty thousand, nine hundred ninety-eight".