19873489 has 2 divisors, whose sum is σ = 19873490. Its totient is φ = 19873488.

The previous prime is 19873481. The next prime is 19873499. The reversal of 19873489 is 98437891.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15272464 + 4601025 = 3908^2 + 2145^2 .

It is an emirp because it is prime and its reverse (98437891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19873489 - 2³ = 19873481 is a prime.

It is not a weakly prime, because it can be changed into another prime (19873481) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9936744 + 9936745.

It is an arithmetic number, because the mean of its divisors is an integer number (9936745).

Almost surely, 2^19873489 is an apocalyptic number.

It is an amenable number.

19873489 is a deficient number, since it is larger than the sum of its proper divisors (1).

19873489 is an equidigital number, since it uses as much as digits as its factorization.

19873489 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 435456, while the sum is 49.

The square root of 19873489 is about 4457.9691564658. The cubic root of 19873489 is about 270.8682111348.

It can be divided in two parts, 1987 and 3489, that added together give a square (5476 = 74²).

The spelling of 19873489 in words is "nineteen million, eight hundred seventy-three thousand, four hundred eighty-nine".