19785454609 has 2 divisors, whose sum is σ = 19785454610. Its totient is φ = 19785454608.

The previous prime is 19785454567. The next prime is 19785454613. The reversal of 19785454609 is 90645458791.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19698964609 + 86490000 = 140353^2 + 9300^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19785454609 is a prime.

It is not a weakly prime, because it can be changed into another prime (19785454639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9892727304 + 9892727305.

It is an arithmetic number, because the mean of its divisors is an integer number (9892727305).

Almost surely, 2^19785454609 is an apocalyptic number.

It is an amenable number.

19785454609 is a deficient number, since it is larger than the sum of its proper divisors (1).

19785454609 is an equidigital number, since it uses as much as digits as its factorization.

19785454609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10886400, while the sum is 58.

The spelling of 19785454609 in words is "nineteen billion, seven hundred eighty-five million, four hundred fifty-four thousand, six hundred nine".