845356781 has 2 divisors, whose sum is σ = 845356782. Its totient is φ = 845356780.

The previous prime is 845356753. The next prime is 845356829. The reversal of 845356781 is 187653548.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 845355625 + 1156 = 29075^2 + 34^2 .

It is a cyclic number.

It is not a de Polignac number, because 845356781 - 2¹⁸ = 845094637 is a prime.

It is a super-2 number, since 2×845356781² = 1429256174365363922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (845356751) 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, 422678390 + 422678391.

It is an arithmetic number, because the mean of its divisors is an integer number (422678391).

Almost surely, 2^845356781 is an apocalyptic number.

It is an amenable number.

845356781 is a deficient number, since it is larger than the sum of its proper divisors (1).

845356781 is an equidigital number, since it uses as much as digits as its factorization.

845356781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 806400, while the sum is 47.

The square root of 845356781 is about 29075.0198796149. The cubic root of 845356781 is about 945.5402343863.

The spelling of 845356781 in words is "eight hundred forty-five million, three hundred fifty-six thousand, seven hundred eighty-one".