911221231 has 2 divisors, whose sum is σ = 911221232. Its totient is φ = 911221230.

The previous prime is 911221217. The next prime is 911221243. The reversal of 911221231 is 132122119.

911221231 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (132122119) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-911221231 is a prime.

It is a super-2 number, since 2×911221231² = 1660648263650310722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (911221261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 455610615 + 455610616.

It is an arithmetic number, because the mean of its divisors is an integer number (455610616).

Almost surely, 2^911221231 is an apocalyptic number.

911221231 is a deficient number, since it is larger than the sum of its proper divisors (1).

911221231 is an equidigital number, since it uses as much as digits as its factorization.

911221231 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 22.

The square root of 911221231 is about 30186.4411781184. The cubic root of 911221231 is about 969.4854077845.

The spelling of 911221231 in words is "nine hundred eleven million, two hundred twenty-one thousand, two hundred thirty-one".