19840459 has 2 divisors, whose sum is σ = 19840460. Its totient is φ = 19840458.

The previous prime is 19840441. The next prime is 19840463. The reversal of 19840459 is 95404891.

It is a strong prime.

It is an emirp because it is prime and its reverse (95404891) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19840459 is a prime.

It is not a weakly prime, because it can be changed into another prime (19840409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9920229 + 9920230.

It is an arithmetic number, because the mean of its divisors is an integer number (9920230).

Almost surely, 2^19840459 is an apocalyptic number.

19840459 is a deficient number, since it is larger than the sum of its proper divisors (1).

19840459 is an equidigital number, since it uses as much as digits as its factorization.

19840459 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 40.

The square root of 19840459 is about 4454.2630142370. The cubic root of 19840459 is about 270.7180657468.

The spelling of 19840459 in words is "nineteen million, eight hundred forty thousand, four hundred fifty-nine".