15509996871197 has 2 divisors, whose sum is σ = 15509996871198. Its totient is φ = 15509996871196.

The previous prime is 15509996871169. The next prime is 15509996871223. The reversal of 15509996871197 is 79117869990551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8589787935556 + 6920208935641 = 2930834^2 + 2630629^2 .

It is a cyclic number.

It is not a de Polignac number, because 15509996871197 - 2⁸ = 15509996870941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15509996871097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7754998435598 + 7754998435599.

It is an arithmetic number, because the mean of its divisors is an integer number (7754998435599).

Almost surely, 2^{15509996871197} is an apocalyptic number.

It is an amenable number.

15509996871197 is a deficient number, since it is larger than the sum of its proper divisors (1).

15509996871197 is an equidigital number, since it uses as much as digits as its factorization.

15509996871197 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 385786800, while the sum is 77.

The spelling of 15509996871197 in words is "fifteen trillion, five hundred nine billion, nine hundred ninety-six million, eight hundred seventy-one thousand, one hundred ninety-seven".