866844262881 has 24 divisors (see below), whose sum is σ = 1325797638984. Its totient is φ = 543887585280.

The previous prime is 866844262799. The next prime is 866844262901. The reversal of 866844262881 is 188262448668.

It can be written as a sum of positive squares in 4 ways, for example, as 799984656 + 866044278225 = 28284^2 + 930615^2 .

It is not a de Polignac number, because 866844262881 - 2¹⁴ = 866844246497 is a prime.

It is a super-2 number, since 2×866844262881² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (866844262381) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9535161 + ... + 9625641.

It is an arithmetic number, because the mean of its divisors is an integer number (55241568291).

Almost surely, 2^866844262881 is an apocalyptic number.

It is an amenable number.

866844262881 is a deficient number, since it is larger than the sum of its proper divisors (458953376103).

866844262881 is a wasteful number, since it uses less digits than its factorization.

866844262881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153121 (or 153118 counting only the distinct ones).

The product of its digits is 56623104, while the sum is 63.

The spelling of 866844262881 in words is "eight hundred sixty-six billion, eight hundred forty-four million, two hundred sixty-two thousand, eight hundred eighty-one".