19945799 has 2 divisors, whose sum is σ = 19945800. Its totient is φ = 19945798.

The previous prime is 19945787. The next prime is 19945829. The reversal of 19945799 is 99754991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19945799 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19945799.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19945399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9972899 + 9972900.

It is an arithmetic number, because the mean of its divisors is an integer number (9972900).

Almost surely, 2^19945799 is an apocalyptic number.

19945799 is a deficient number, since it is larger than the sum of its proper divisors (1).

19945799 is an equidigital number, since it uses as much as digits as its factorization.

19945799 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 918540, while the sum is 53.

The square root of 19945799 is about 4466.0719877763. The cubic root of 19945799 is about 271.1963329023.

The spelling of 19945799 in words is "nineteen million, nine hundred forty-five thousand, seven hundred ninety-nine".