19994539 has 2 divisors, whose sum is σ = 19994540. Its totient is φ = 19994538.

The previous prime is 19994537. The next prime is 19994549. The reversal of 19994539 is 93549991.

It is a weak prime.

It is an emirp because it is prime and its reverse (93549991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19994539 - 2¹ = 19994537 is a prime.

Together with 19994537, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 19994492 and 19994501.

It is not a weakly prime, because it can be changed into another prime (19994531) 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, 9997269 + 9997270.

It is an arithmetic number, because the mean of its divisors is an integer number (9997270).

Almost surely, 2^19994539 is an apocalyptic number.

19994539 is a deficient number, since it is larger than the sum of its proper divisors (1).

19994539 is an equidigital number, since it uses as much as digits as its factorization.

19994539 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 393660, while the sum is 49.

The square root of 19994539 is about 4471.5253549544. The cubic root of 19994539 is about 271.4170536862.

The spelling of 19994539 in words is "nineteen million, nine hundred ninety-four thousand, five hundred thirty-nine".