19995889 has 2 divisors, whose sum is σ = 19995890. Its totient is φ = 19995888.

The previous prime is 19995883. The next prime is 19995919. The reversal of 19995889 is 98859991.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10336225 + 9659664 = 3215^2 + 3108^2 .

It is an emirp because it is prime and its reverse (98859991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19995889 - 2³ = 19995881 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19995881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9997944 + 9997945.

It is an arithmetic number, because the mean of its divisors is an integer number (9997945).

Almost surely, 2^19995889 is an apocalyptic number.

It is an amenable number.

19995889 is a deficient number, since it is larger than the sum of its proper divisors (1).

19995889 is an equidigital number, since it uses as much as digits as its factorization.

19995889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2099520, while the sum is 58.

The square root of 19995889 is about 4471.6763076055. The cubic root of 19995889 is about 271.4231621003.

The spelling of 19995889 in words is "nineteen million, nine hundred ninety-five thousand, eight hundred eighty-nine".