19984358609 has 4 divisors (see below), whose sum is σ = 19984809780. Its totient is φ = 19983907440.

The previous prime is 19984358587. The next prime is 19984358629. The reversal of 19984358609 is 90685348991.

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 6103984384 + 13880374225 = 78128^2 + 117815^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19984358609 is a prime.

It is a super-2 number, since 2×19984358609² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19984358629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 150902 + ... + 250479.

It is an arithmetic number, because the mean of its divisors is an integer number (4996202445).

Almost surely, 2^19984358609 is an apocalyptic number.

It is an amenable number.

19984358609 is a deficient number, since it is larger than the sum of its proper divisors (451171).

19984358609 is an equidigital number, since it uses as much as digits as its factorization.

19984358609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451170.

The product of its (nonzero) digits is 16796160, while the sum is 62.

The spelling of 19984358609 in words is "nineteen billion, nine hundred eighty-four million, three hundred fifty-eight thousand, six hundred nine".