19798109 has 2 divisors, whose sum is σ = 19798110. Its totient is φ = 19798108.

The previous prime is 19798091. The next prime is 19798117. The reversal of 19798109 is 90189791.

Together with previous prime (19798091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12802084 + 6996025 = 3578^2 + 2645^2 .

It is a cyclic number.

It is not a de Polignac number, because 19798109 - 2²⁴ = 3020893 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19798109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19798159) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9899054 + 9899055.

It is an arithmetic number, because the mean of its divisors is an integer number (9899055).

Almost surely, 2^19798109 is an apocalyptic number.

It is an amenable number.

19798109 is a deficient number, since it is larger than the sum of its proper divisors (1).

19798109 is an equidigital number, since it uses as much as digits as its factorization.

19798109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 19798109 is about 4449.5066018605. The cubic root of 19798109 is about 270.5253101733.

The spelling of 19798109 in words is "nineteen million, seven hundred ninety-eight thousand, one hundred nine".