19990459 has 2 divisors, whose sum is σ = 19990460. Its totient is φ = 19990458.

The previous prime is 19990457. The next prime is 19990499. The reversal of 19990459 is 95409991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 19990459 - 2¹ = 19990457 is a prime.

Together with 19990457, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19990457) 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, 9995229 + 9995230.

It is an arithmetic number, because the mean of its divisors is an integer number (9995230).

Almost surely, 2^19990459 is an apocalyptic number.

19990459 is a deficient number, since it is larger than the sum of its proper divisors (1).

19990459 is an equidigital number, since it uses as much as digits as its factorization.

19990459 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 131220, while the sum is 46.

The square root of 19990459 is about 4471.0691115213. The cubic root of 19990459 is about 271.3985910298.

It can be divided in two parts, 19990 and 459, that added together give a square (20449 = 143²).

The spelling of 19990459 in words is "nineteen million, nine hundred ninety thousand, four hundred fifty-nine".