19421239 has 2 divisors, whose sum is σ = 19421240. Its totient is φ = 19421238.

The previous prime is 19421231. The next prime is 19421323. The reversal of 19421239 is 93212491.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19421239 - 2³ = 19421231 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19421239.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19421231) 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, 9710619 + 9710620.

It is an arithmetic number, because the mean of its divisors is an integer number (9710620).

Almost surely, 2^19421239 is an apocalyptic number.

19421239 is a deficient number, since it is larger than the sum of its proper divisors (1).

19421239 is an equidigital number, since it uses as much as digits as its factorization.

19421239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 31.

The square root of 19421239 is about 4406.9534828496. The cubic root of 19421239 is about 268.7977593867.

The spelling of 19421239 in words is "nineteen million, four hundred twenty-one thousand, two hundred thirty-nine".