111312221 has 2 divisors, whose sum is σ = 111312222. Its totient is φ = 111312220.

The previous prime is 111312197. The next prime is 111312233. The reversal of 111312221 is 122213111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 97732996 + 13579225 = 9886^2 + 3685^2 .

It is a cyclic number.

It is not a de Polignac number, because 111312221 - 2¹⁰ = 111311197 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111312196 and 111312205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111315221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55656110 + 55656111.

It is an arithmetic number, because the mean of its divisors is an integer number (55656111).

Almost surely, 2^111312221 is an apocalyptic number.

It is an amenable number.

111312221 is a deficient number, since it is larger than the sum of its proper divisors (1).

111312221 is an equidigital number, since it uses as much as digits as its factorization.

111312221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24, while the sum is 14.

The square root of 111312221 is about 10550.4607008415. The cubic root of 111312221 is about 481.0397325996.

Adding to 111312221 its reverse (122213111), we get a palindrome (233525332).

The spelling of 111312221 in words is "one hundred eleven million, three hundred twelve thousand, two hundred twenty-one".