225168991 has 2 divisors, whose sum is σ = 225168992. Its totient is φ = 225168990.

The previous prime is 225168973. The next prime is 225168997. The reversal of 225168991 is 199861522.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 225168991 - 2¹¹ = 225166943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (225168997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 112584495 + 112584496.

It is an arithmetic number, because the mean of its divisors is an integer number (112584496).

Almost surely, 2^225168991 is an apocalyptic number.

225168991 is a deficient number, since it is larger than the sum of its proper divisors (1).

225168991 is an equidigital number, since it uses as much as digits as its factorization.

225168991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 43.

The square root of 225168991 is about 15005.6319760282. The cubic root of 225168991 is about 608.3724336578.

The spelling of 225168991 in words is "two hundred twenty-five million, one hundred sixty-eight thousand, nine hundred ninety-one".