845394391 has 2 divisors, whose sum is σ = 845394392. Its totient is φ = 845394390.

The previous prime is 845394383. The next prime is 845394419. The reversal of 845394391 is 193493548.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 845394391 - 2³ = 845394383 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (845394691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422697195 + 422697196.

It is an arithmetic number, because the mean of its divisors is an integer number (422697196).

Almost surely, 2^845394391 is an apocalyptic number.

845394391 is a deficient number, since it is larger than the sum of its proper divisors (1).

845394391 is an equidigital number, since it uses as much as digits as its factorization.

845394391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 466560, while the sum is 46.

The square root of 845394391 is about 29075.6666475594. Note that the first 4 decimals coincide. The cubic root of 845394391 is about 945.5542565687.

The spelling of 845394391 in words is "eight hundred forty-five million, three hundred ninety-four thousand, three hundred ninety-one".