331456561 has 2 divisors, whose sum is σ = 331456562. Its totient is φ = 331456560.

The previous prime is 331456537. The next prime is 331456591. The reversal of 331456561 is 165654133.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 180633600 + 150822961 = 13440^2 + 12281^2 .

It is an emirp because it is prime and its reverse (165654133) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 331456561 - 2⁵ = 331456529 is a prime.

It is not a weakly prime, because it can be changed into another prime (331456591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165728280 + 165728281.

It is an arithmetic number, because the mean of its divisors is an integer number (165728281).

Almost surely, 2^331456561 is an apocalyptic number.

It is an amenable number.

331456561 is a deficient number, since it is larger than the sum of its proper divisors (1).

331456561 is an equidigital number, since it uses as much as digits as its factorization.

331456561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32400, while the sum is 34.

The square root of 331456561 is about 18205.9485059142. The cubic root of 331456561 is about 692.0575432174.

The spelling of 331456561 in words is "three hundred thirty-one million, four hundred fifty-six thousand, five hundred sixty-one".