19768909 has 4 divisors (see below), whose sum is σ = 20931804. Its totient is φ = 18606016.

The previous prime is 19768907. The next prime is 19768913. The reversal of 19768909 is 90986791.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 10220809 + 9548100 = 3197^2 + 3090^2 .

It is a cyclic number.

It is not a de Polignac number, because 19768909 - 2¹ = 19768907 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19768907) 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 in 3 ways as a sum of consecutive naturals, for example, 581422 + ... + 581455.

It is an arithmetic number, because the mean of its divisors is an integer number (5232951).

Almost surely, 2^19768909 is an apocalyptic number.

It is an amenable number.

19768909 is a deficient number, since it is larger than the sum of its proper divisors (1162895).

19768909 is a wasteful number, since it uses less digits than its factorization.

19768909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162894.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 19768909 is about 4446.2241284038. The cubic root of 19768909 is about 270.3922465259.

The spelling of 19768909 in words is "nineteen million, seven hundred sixty-eight thousand, nine hundred nine".