19998331 has 4 divisors (see below), whose sum is σ = 20375712. Its totient is φ = 19620952.

The previous prime is 19998263. The next prime is 19998337. The reversal of 19998331 is 13389991.

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

It is a cyclic number.

It is not a de Polignac number, because 19998331 - 2¹⁷ = 19867259 is a prime.

It is a super-2 number, since 2×19998331² = 799866485571122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19998337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 188611 + ... + 188716.

It is an arithmetic number, because the mean of its divisors is an integer number (5093928).

Almost surely, 2^19998331 is an apocalyptic number.

19998331 is a deficient number, since it is larger than the sum of its proper divisors (377381).

19998331 is an equidigital number, since it uses as much as digits as its factorization.

19998331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 377380.

The product of its digits is 52488, while the sum is 43.

The square root of 19998331 is about 4471.9493512338. The cubic root of 19998331 is about 271.4342108444.

The spelling of 19998331 in words is "nineteen million, nine hundred ninety-eight thousand, three hundred thirty-one".