19869709 has 2 divisors, whose sum is σ = 19869710. Its totient is φ = 19869708.

The previous prime is 19869697. The next prime is 19869749. The reversal of 19869709 is 90796891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14478025 + 5391684 = 3805^2 + 2322^2 .

It is a cyclic number.

It is not a de Polignac number, because 19869709 - 2⁹ = 19869197 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19869749) 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, 9934854 + 9934855.

It is an arithmetic number, because the mean of its divisors is an integer number (9934855).

Almost surely, 2^19869709 is an apocalyptic number.

It is an amenable number.

19869709 is a deficient number, since it is larger than the sum of its proper divisors (1).

19869709 is an equidigital number, since it uses as much as digits as its factorization.

19869709 is an odious number, because the sum of its binary digits is odd.

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

The square root of 19869709 is about 4457.5451764396. The cubic root of 19869709 is about 270.8510367179.

The spelling of 19869709 in words is "nineteen million, eight hundred sixty-nine thousand, seven hundred nine".