13111311221 has 8 divisors (see below), whose sum is σ = 13170502488. Its totient is φ = 13052160000.

The previous prime is 13111311193. The next prime is 13111311289. The reversal of 13111311221 is 12211311131.

It can be written as a sum of positive squares in 4 ways, for example, as 1282356100 + 11828955121 = 35810^2 + 108761^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13111311221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13111311221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13111391221) 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, 787301 + ... + 803781.

It is an arithmetic number, because the mean of its divisors is an integer number (1646312811).

Almost surely, 2^13111311221 is an apocalyptic number.

It is an amenable number.

13111311221 is a deficient number, since it is larger than the sum of its proper divisors (59191267).

13111311221 is a wasteful number, since it uses less digits than its factorization.

13111311221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20023.

The product of its digits is 36, while the sum is 17.

Adding to 13111311221 its reverse (12211311131), we get a palindrome (25322622352).

The spelling of 13111311221 in words is "thirteen billion, one hundred eleven million, three hundred eleven thousand, two hundred twenty-one".