201998 has 4 divisors (see below), whose sum is σ = 303000. Its totient is φ = 100998.

The previous prime is 201997. The next prime is 202001. The reversal of 201998 is 899102.

It is a semiprime because it is the product of two primes.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 201998.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50498 + ... + 50501.

It is an arithmetic number, because the mean of its divisors is an integer number (75750).

2²⁰¹⁹⁹⁸ is an apocalyptic number.

201998 is a deficient number, since it is larger than the sum of its proper divisors (101002).

201998 is a wasteful number, since it uses less digits than its factorization.

201998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101001.

The product of its (nonzero) digits is 1296, while the sum is 29.

The square root of 201998 is about 449.4418761086. The cubic root of 201998 is about 58.6744494381.

The spelling of 201998 in words is "two hundred one thousand, nine hundred ninety-eight".