81122216231 has 8 divisors (see below), whose sum is σ = 92734732320. Its totient is φ = 69515607168.

The previous prime is 81122216221. The next prime is 81122216239. The reversal of 81122216231 is 13261222118.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-81122216231 is a prime.

It is a super-2 number, since 2×81122216231² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81122216194 and 81122216203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81122216239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1447286 + ... + 1502291.

It is an arithmetic number, because the mean of its divisors is an integer number (11591841540).

Almost surely, 2^81122216231 is an apocalyptic number.

81122216231 is a deficient number, since it is larger than the sum of its proper divisors (11612516089).

81122216231 is a wasteful number, since it uses less digits than its factorization.

81122216231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2953513.

The product of its digits is 2304, while the sum is 29.

Adding to 81122216231 its reverse (13261222118), we get a palindrome (94383438349).

The spelling of 81122216231 in words is "eighty-one billion, one hundred twenty-two million, two hundred sixteen thousand, two hundred thirty-one".