11312221 has 2 divisors, whose sum is σ = 11312222. Its totient is φ = 11312220.

The previous prime is 11312209. The next prime is 11312261. The reversal of 11312221 is 12221311.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6200100 + 5112121 = 2490^2 + 2261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11312221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11312261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5656110 + 5656111.

It is an arithmetic number, because the mean of its divisors is an integer number (5656111).

Almost surely, 2^11312221 is an apocalyptic number.

It is an amenable number.

11312221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11312221 is an equidigital number, since it uses as much as digits as its factorization.

11312221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24, while the sum is 13.

The square root of 11312221 is about 3363.3645356993. The cubic root of 11312221 is about 224.4825706579.

Adding to 11312221 its reverse (12221311), we get a palindrome (23533532).

The spelling of 11312221 in words is "eleven million, three hundred twelve thousand, two hundred twenty-one".