19814909 has 2 divisors, whose sum is σ = 19814910. Its totient is φ = 19814908.

The previous prime is 19814903. The next prime is 19814933. The reversal of 19814909 is 90941891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19166884 + 648025 = 4378^2 + 805^2 .

It is a cyclic number.

It is not a de Polignac number, because 19814909 - 2²⁰ = 18766333 is a prime.

It is a super-3 number, since 3×19814909³ (a number of 23 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19814903) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9907454 + 9907455.

It is an arithmetic number, because the mean of its divisors is an integer number (9907455).

Almost surely, 2^19814909 is an apocalyptic number.

It is an amenable number.

19814909 is a deficient number, since it is larger than the sum of its proper divisors (1).

19814909 is an equidigital number, since it uses as much as digits as its factorization.

19814909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 19814909 is about 4451.3940513057. The cubic root of 19814909 is about 270.6018080565.

The spelling of 19814909 in words is "nineteen million, eight hundred fourteen thousand, nine hundred nine".