18001898 has 12 divisors (see below), whose sum is σ = 27274338. Its totient is φ = 8911080.

The previous prime is 18001891. The next prime is 18001901. The reversal of 18001898 is 89810081.

It can be written as a sum of positive squares in only one way, i.e., 17952169 + 49729 = 4237^2 + 223^2 .

It is not an unprimeable number, because it can be changed into a prime (18001891) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 80615 + ... + 80837.

Almost surely, 2^18001898 is an apocalyptic number.

18001898 is a deficient number, since it is larger than the sum of its proper divisors (9272440).

18001898 is an equidigital number, since it uses as much as digits as its factorization.

18001898 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 35.

The square root of 18001898 is about 4242.8643626682. The cubic root of 18001898 is about 262.0833505178.

The spelling of 18001898 in words is "eighteen million, one thousand, eight hundred ninety-eight".