999113221 has 2 divisors, whose sum is σ = 999113222. Its totient is φ = 999113220.

The previous prime is 999113177. The next prime is 999113243. The reversal of 999113221 is 122311999.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 838102500 + 161010721 = 28950^2 + 12689^2 .

It is a cyclic number.

It is not a de Polignac number, because 999113221 - 2¹¹ = 999111173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999113321) 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, 499556610 + 499556611.

It is an arithmetic number, because the mean of its divisors is an integer number (499556611).

Almost surely, 2^999113221 is an apocalyptic number.

It is an amenable number.

999113221 is a deficient number, since it is larger than the sum of its proper divisors (1).

999113221 is an equidigital number, since it uses as much as digits as its factorization.

999113221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8748, while the sum is 37.

The square root of 999113221 is about 31608.7522847707. The cubic root of 999113221 is about 999.7043195817.

The spelling of 999113221 in words is "nine hundred ninety-nine million, one hundred thirteen thousand, two hundred twenty-one".