866111236831 has 24 divisors (see below), whose sum is σ = 917221669920. Its totient is φ = 816286344192.

The previous prime is 866111236819. The next prime is 866111236853. The reversal of 866111236831 is 138632111668.

It is a happy number.

It is not a de Polignac number, because 866111236831 - 2¹³ = 866111228639 is a prime.

It is a super-2 number, since 2×866111236831² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (866111236231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49548465 + ... + 49565941.

It is an arithmetic number, because the mean of its divisors is an integer number (38217569580).

Almost surely, 2^866111236831 is an apocalyptic number.

866111236831 is a deficient number, since it is larger than the sum of its proper divisors (51110433089).

866111236831 is a wasteful number, since it uses less digits than its factorization.

866111236831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17923 (or 17826 counting only the distinct ones).

The product of its digits is 248832, while the sum is 46.

The spelling of 866111236831 in words is "eight hundred sixty-six billion, one hundred eleven million, two hundred thirty-six thousand, eight hundred thirty-one".