18899999 has 2 divisors, whose sum is σ = 18900000. Its totient is φ = 18899998.

The previous prime is 18899989. The next prime is 18900053. The reversal of 18899999 is 99999881.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18899999 - 2⁸ = 18899743 is a prime.

It is a Chen prime.

18899999 is a modest number, since divided by 9999 gives 1889 as remainder.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18899929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9449999 + 9450000.

It is an arithmetic number, because the mean of its divisors is an integer number (9450000).

Almost surely, 2^18899999 is an apocalyptic number.

18899999 is a deficient number, since it is larger than the sum of its proper divisors (1).

18899999 is an equidigital number, since it uses as much as digits as its factorization.

18899999 is an evil number, because the sum of its binary digits is even.

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

The square root of 18899999 is about 4347.4129088459. The cubic root of 18899999 is about 266.3711958249.

The spelling of 18899999 in words is "eighteen million, eight hundred ninety-nine thousand, nine hundred ninety-nine".