19872389 has 2 divisors, whose sum is σ = 19872390. Its totient is φ = 19872388.

The previous prime is 19872383. The next prime is 19872421. The reversal of 19872389 is 98327891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19651489 + 220900 = 4433^2 + 470^2 .

It is a cyclic number.

It is not a de Polignac number, because 19872389 - 2⁴ = 19872373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19872383) 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, 9936194 + 9936195.

It is an arithmetic number, because the mean of its divisors is an integer number (9936195).

Almost surely, 2^19872389 is an apocalyptic number.

It is an amenable number.

19872389 is a deficient number, since it is larger than the sum of its proper divisors (1).

19872389 is an equidigital number, since it uses as much as digits as its factorization.

19872389 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 217728, while the sum is 47.

The square root of 19872389 is about 4457.8457801947. The cubic root of 19872389 is about 270.8632135133.

The spelling of 19872389 in words is "nineteen million, eight hundred seventy-two thousand, three hundred eighty-nine".