15855217886873 has 2 divisors, whose sum is σ = 15855217886874. Its totient is φ = 15855217886872.

The previous prime is 15855217886813. The next prime is 15855217886923. The reversal of 15855217886873 is 37868871255851.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11704903665049 + 4150314221824 = 3421243^2 + 2037232^2 .

It is a cyclic number.

It is not a de Polignac number, because 15855217886873 - 2²² = 15855213692569 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 15855217886873.

It is not a weakly prime, because it can be changed into another prime (15855217886813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7927608943436 + 7927608943437.

It is an arithmetic number, because the mean of its divisors is an integer number (7927608943437).

Almost surely, 2^{15855217886873} is an apocalyptic number.

It is an amenable number.

15855217886873 is a deficient number, since it is larger than the sum of its proper divisors (1).

15855217886873 is an equidigital number, since it uses as much as digits as its factorization.

15855217886873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 903168000, while the sum is 74.

The spelling of 15855217886873 in words is "fifteen trillion, eight hundred fifty-five billion, two hundred seventeen million, eight hundred eighty-six thousand, eight hundred seventy-three".