19909289 has 2 divisors, whose sum is σ = 19909290. Its totient is φ = 19909288.

The previous prime is 19909277. The next prime is 19909303. The reversal of 19909289 is 98290991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19891600 + 17689 = 4460^2 + 133^2 .

It is a cyclic number.

It is not a de Polignac number, because 19909289 - 2¹⁶ = 19843753 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (19909229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9954644 + 9954645.

It is an arithmetic number, because the mean of its divisors is an integer number (9954645).

Almost surely, 2^19909289 is an apocalyptic number.

It is an amenable number.

19909289 is a deficient number, since it is larger than the sum of its proper divisors (1).

19909289 is an equidigital number, since it uses as much as digits as its factorization.

19909289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 104976, while the sum is 47.

The square root of 19909289 is about 4461.9826310733. The cubic root of 19909289 is about 271.0307604322.

The spelling of 19909289 in words is "nineteen million, nine hundred nine thousand, two hundred eighty-nine".