19998149 has 2 divisors, whose sum is σ = 19998150. Its totient is φ = 19998148.

The previous prime is 19998047. The next prime is 19998151. The reversal of 19998149 is 94189991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10956100 + 9042049 = 3310^2 + 3007^2 .

It is a cyclic number.

It is not a de Polignac number, because 19998149 - 2⁸ = 19997893 is a prime.

It is a super-3 number, since 3×19998149³ (a number of 23 digits) contains 333 as substring.

Together with 19998151, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 19998097 and 19998106.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19998169) 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 as a sum of consecutive naturals, namely, 9999074 + 9999075.

It is an arithmetic number, because the mean of its divisors is an integer number (9999075).

Almost surely, 2^19998149 is an apocalyptic number.

It is an amenable number.

19998149 is a deficient number, since it is larger than the sum of its proper divisors (1).

19998149 is an equidigital number, since it uses as much as digits as its factorization.

19998149 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 50.

The square root of 19998149 is about 4471.9290021198. The cubic root of 19998149 is about 271.4333874228.

The spelling of 19998149 in words is "nineteen million, nine hundred ninety-eight thousand, one hundred forty-nine".