19898939 has 2 divisors, whose sum is σ = 19898940. Its totient is φ = 19898938.

The previous prime is 19898929. The next prime is 19898941. The reversal of 19898939 is 93989891.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19898939 is a prime.

Together with 19898941, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19898929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9949469 + 9949470.

It is an arithmetic number, because the mean of its divisors is an integer number (9949470).

Almost surely, 2^19898939 is an apocalyptic number.

19898939 is a deficient number, since it is larger than the sum of its proper divisors (1).

19898939 is an equidigital number, since it uses as much as digits as its factorization.

19898939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1259712, while the sum is 56.

The square root of 19898939 is about 4460.8226819725. The cubic root of 19898939 is about 270.9837864693.

The spelling of 19898939 in words is "nineteen million, eight hundred ninety-eight thousand, nine hundred thirty-nine".