831406561 has 2 divisors, whose sum is σ = 831406562. Its totient is φ = 831406560.

The previous prime is 831406559. The next prime is 831406619. The reversal of 831406561 is 165604138.

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., 798401536 + 33005025 = 28256^2 + 5745^2 .

It is a cyclic number.

It is not a de Polignac number, because 831406561 - 2¹ = 831406559 is a prime.

Together with 831406559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (831406061) 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, 415703280 + 415703281.

It is an arithmetic number, because the mean of its divisors is an integer number (415703281).

Almost surely, 2^831406561 is an apocalyptic number.

It is an amenable number.

831406561 is a deficient number, since it is larger than the sum of its proper divisors (1).

831406561 is an equidigital number, since it uses as much as digits as its factorization.

831406561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 831406561 is about 28834.1214709240. The cubic root of 831406561 is about 940.3102043198.

The spelling of 831406561 in words is "eight hundred thirty-one million, four hundred six thousand, five hundred sixty-one".