844427813 has 2 divisors, whose sum is σ = 844427814. Its totient is φ = 844427812.

The previous prime is 844427809. The next prime is 844427821. The reversal of 844427813 is 318724448.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 840594049 + 3833764 = 28993^2 + 1958^2 .

It is a cyclic number.

It is not a de Polignac number, because 844427813 - 2² = 844427809 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (844427833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 422213906 + 422213907.

It is an arithmetic number, because the mean of its divisors is an integer number (422213907).

Almost surely, 2^844427813 is an apocalyptic number.

It is an amenable number.

844427813 is a deficient number, since it is larger than the sum of its proper divisors (1).

844427813 is an equidigital number, since it uses as much as digits as its factorization.

844427813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172032, while the sum is 41.

The square root of 844427813 is about 29059.0401252347. The cubic root of 844427813 is about 945.1937540252.

The spelling of 844427813 in words is "eight hundred forty-four million, four hundred twenty-seven thousand, eight hundred thirteen".