11312331221 has 4 divisors (see below), whose sum is σ = 11356348332. Its totient is φ = 11268314112.

The previous prime is 11312331209. The next prime is 11312331259. The reversal of 11312331221 is 12213321311.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12213321311 = 223 ⋅54768257.

It can be written as a sum of positive squares in 2 ways, for example, as 11233032196 + 79299025 = 105986^2 + 8905^2 .

It is a cyclic number.

It is not a de Polignac number, because 11312331221 - 2⁶ = 11312331157 is a prime.

It is a super-2 number, since 2×11312331221² (a number of 21 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 = 11312331193 and 11312331202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11312331521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22008170 + ... + 22008683.

It is an arithmetic number, because the mean of its divisors is an integer number (2839087083).

Almost surely, 2^11312331221 is an apocalyptic number.

It is an amenable number.

11312331221 is a deficient number, since it is larger than the sum of its proper divisors (44017111).

11312331221 is an equidigital number, since it uses as much as digits as its factorization.

11312331221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44017110.

The product of its digits is 216, while the sum is 20.

Adding to 11312331221 its reverse (12213321311), we get a palindrome (23525652532).

The spelling of 11312331221 in words is "eleven billion, three hundred twelve million, three hundred thirty-one thousand, two hundred twenty-one".