81118221245 has 8 divisors (see below), whose sum is σ = 98203298616. Its totient is φ = 64320288256.

The previous prime is 81118221211. The next prime is 81118221257. The reversal of 81118221245 is 54212281118.

It can be written as a sum of positive squares in 4 ways, for example, as 15155449 + 81103065796 = 3893^2 + 284786^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81118221245 - 2¹⁶ = 81118155709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 71785472 + ... + 71786601.

It is an arithmetic number, because the mean of its divisors is an integer number (12275412327).

Almost surely, 2^81118221245 is an apocalyptic number.

It is an amenable number.

81118221245 is a deficient number, since it is larger than the sum of its proper divisors (17085077371).

81118221245 is a wasteful number, since it uses less digits than its factorization.

81118221245 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143572191.

The product of its digits is 10240, while the sum is 35.

The spelling of 81118221245 in words is "eighty-one billion, one hundred eighteen million, two hundred twenty-one thousand, two hundred forty-five".