19998899 has 2 divisors, whose sum is σ = 19998900. Its totient is φ = 19998898.

The previous prime is 19998877. The next prime is 19998917. The reversal of 19998899 is 99889991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19998899 - 2¹² = 19994803 is a prime.

It is a super-2 number, since 2×19998899² = 799911922424402, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (19998809) 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, 9999449 + 9999450.

It is an arithmetic number, because the mean of its divisors is an integer number (9999450).

Almost surely, 2^19998899 is an apocalyptic number.

19998899 is a deficient number, since it is larger than the sum of its proper divisors (1).

19998899 is an equidigital number, since it uses as much as digits as its factorization.

19998899 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3779136, while the sum is 62.

The square root of 19998899 is about 4472.0128577633. The cubic root of 19998899 is about 271.4367806118.

The spelling of 19998899 in words is "nineteen million, nine hundred ninety-eight thousand, eight hundred ninety-nine".