19889239 has 4 divisors (see below), whose sum is σ = 20426824. Its totient is φ = 19351656.

The previous prime is 19889237. The next prime is 19889251. The reversal of 19889239 is 93298891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19889239 - 2¹ = 19889237 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19889192 and 19889201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19889237) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 268737 + ... + 268810.

It is an arithmetic number, because the mean of its divisors is an integer number (5106706).

Almost surely, 2^19889239 is an apocalyptic number.

19889239 is a deficient number, since it is larger than the sum of its proper divisors (537585).

19889239 is an equidigital number, since it uses as much as digits as its factorization.

19889239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537584.

The product of its digits is 279936, while the sum is 49.

The square root of 19889239 is about 4459.7353060468. The cubic root of 19889239 is about 270.9397477738.

The spelling of 19889239 in words is "nineteen million, eight hundred eighty-nine thousand, two hundred thirty-nine".