19998151 has 2 divisors, whose sum is σ = 19998152. Its totient is φ = 19998150.

The previous prime is 19998149. The next prime is 19998161. The reversal of 19998151 is 15189991.

It is a weak prime.

It is an emirp because it is prime and its reverse (15189991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19998151 - 2¹ = 19998149 is a prime.

Together with 19998149, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 19998098 and 19998107.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19998161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9999075 + 9999076.

It is an arithmetic number, because the mean of its divisors is an integer number (9999076).

Almost surely, 2^19998151 is an apocalyptic number.

19998151 is a deficient number, since it is larger than the sum of its proper divisors (1).

19998151 is an equidigital number, since it uses as much as digits as its factorization.

19998151 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29160, while the sum is 43.

The square root of 19998151 is about 4471.9292257369. The cubic root of 19998151 is about 271.4333964714.

The spelling of 19998151 in words is "nineteen million, nine hundred ninety-eight thousand, one hundred fifty-one".