19798439 has 2 divisors, whose sum is σ = 19798440. Its totient is φ = 19798438.

The previous prime is 19798409. The next prime is 19798451. The reversal of 19798439 is 93489791.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19798439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19798409) 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, 9899219 + 9899220.

It is an arithmetic number, because the mean of its divisors is an integer number (9899220).

Almost surely, 2^19798439 is an apocalyptic number.

19798439 is a deficient number, since it is larger than the sum of its proper divisors (1).

19798439 is an equidigital number, since it uses as much as digits as its factorization.

19798439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 50.

The square root of 19798439 is about 4449.5436844692. The cubic root of 19798439 is about 270.5268132269.

The spelling of 19798439 in words is "nineteen million, seven hundred ninety-eight thousand, four hundred thirty-nine".