19799749 has 2 divisors, whose sum is σ = 19799750. Its totient is φ = 19799748.

The previous prime is 19799723. The next prime is 19799783. The reversal of 19799749 is 94799791.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19448100 + 351649 = 4410^2 + 593^2 .

It is an emirp because it is prime and its reverse (94799791) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19799749 - 2¹⁹ = 19275461 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19799749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19799149) 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, 9899874 + 9899875.

It is an arithmetic number, because the mean of its divisors is an integer number (9899875).

Almost surely, 2^19799749 is an apocalyptic number.

It is an amenable number.

19799749 is a deficient number, since it is larger than the sum of its proper divisors (1).

19799749 is an equidigital number, since it uses as much as digits as its factorization.

19799749 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1285956, while the sum is 55.

The square root of 19799749 is about 4449.6908881404. The cubic root of 19799749 is about 270.5327797295.

The spelling of 19799749 in words is "nineteen million, seven hundred ninety-nine thousand, seven hundred forty-nine".