2166281286625 has 8 divisors (see below), whose sum is σ = 2703519045864. Its totient is φ = 1733025029200.

The previous prime is 2166281286623. The next prime is 2166281286629. The reversal of 2166281286625 is 5266821826612.

It can be written as a sum of positive squares in 4 ways, for example, as 2931572736 + 2163349713889 = 54144^2 + 1470833^2 .

It is not a de Polignac number, because 2166281286625 - 2¹ = 2166281286623 is a prime.

It is a super-2 number, since 2×2166281286625² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2166281286623) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8665125022 + ... + 8665125271.

It is an arithmetic number, because the mean of its divisors is an integer number (337939880733).

Almost surely, 2^{2166281286625} is an apocalyptic number.

2166281286625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2166281286625 is a deficient number, since it is larger than the sum of its proper divisors (537237759239).

2166281286625 is an equidigital number, since it uses as much as digits as its factorization.

2166281286625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17330250308 (or 17330250298 counting only the distinct ones).

The product of its digits is 6635520, while the sum is 55.

The spelling of 2166281286625 in words is "two trillion, one hundred sixty-six billion, two hundred eighty-one million, two hundred eighty-six thousand, six hundred twenty-five".