12563818909 has 2 divisors, whose sum is σ = 12563818910. Its totient is φ = 12563818908.

The previous prime is 12563818853. The next prime is 12563818921. The reversal of 12563818909 is 90981836521.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10393190809 + 2170628100 = 101947^2 + 46590^2 .

It is a cyclic number.

It is not a de Polignac number, because 12563818909 - 2¹³ = 12563810717 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12563818999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6281909454 + 6281909455.

It is an arithmetic number, because the mean of its divisors is an integer number (6281909455).

Almost surely, 2^12563818909 is an apocalyptic number.

It is an amenable number.

12563818909 is a deficient number, since it is larger than the sum of its proper divisors (1).

12563818909 is an equidigital number, since it uses as much as digits as its factorization.

12563818909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 933120, while the sum is 52.

The spelling of 12563818909 in words is "twelve billion, five hundred sixty-three million, eight hundred eighteen thousand, nine hundred nine".