20198999 has 2 divisors, whose sum is σ = 20199000. Its totient is φ = 20198998.

The previous prime is 20198987. The next prime is 20199007. The reversal of 20198999 is 99989102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20198999 - 2⁸ = 20198743 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20198099) 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 as a sum of consecutive naturals, namely, 10099499 + 10099500.

It is an arithmetic number, because the mean of its divisors is an integer number (10099500).

Almost surely, 2^20198999 is an apocalyptic number.

20198999 is a deficient number, since it is larger than the sum of its proper divisors (1).

20198999 is an equidigital number, since it uses as much as digits as its factorization.

20198999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 47.

The square root of 20198999 is about 4494.3296496808. The cubic root of 20198999 is about 272.3390694702.

The spelling of 20198999 in words is "twenty million, one hundred ninety-eight thousand, nine hundred ninety-nine".