19998231 has 16 divisors (see below), whose sum is σ = 29163648. Its totient is φ = 12088800.

The previous prime is 19998229. The next prime is 19998263. The reversal of 19998231 is 13289991.

It is not a de Polignac number, because 19998231 - 2¹ = 19998229 is a prime.

It is a super-2 number, since 2×19998231² = 799858486258722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19998221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22365 + ... + 23241.

It is an arithmetic number, because the mean of its divisors is an integer number (1822728).

Almost surely, 2^19998231 is an apocalyptic number.

19998231 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19998231 is a deficient number, since it is larger than the sum of its proper divisors (9165417).

19998231 is a wasteful number, since it uses less digits than its factorization.

19998231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1582.

The product of its digits is 34992, while the sum is 42.

The square root of 19998231 is about 4471.9381704134. The cubic root of 19998231 is about 271.4337584156.

The spelling of 19998231 in words is "nineteen million, nine hundred ninety-eight thousand, two hundred thirty-one".