581521 has 2 divisors, whose sum is σ = 581522. Its totient is φ = 581520.

The previous prime is 581491. The next prime is 581527. The reversal of 581521 is 125185.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 440896 + 140625 = 664^2 + 375^2 .

It is a cyclic number.

It is not a de Polignac number, because 581521 - 2⁷ = 581393 is a prime.

It is a Chen prime.

581521 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 581492 and 581501.

It is not a weakly prime, because it can be changed into another prime (581527) 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, 290760 + 290761.

It is an arithmetic number, because the mean of its divisors is an integer number (290761).

2⁵⁸¹⁵²¹ is an apocalyptic number.

It is an amenable number.

581521 is a deficient number, since it is larger than the sum of its proper divisors (1).

581521 is an equidigital number, since it uses as much as digits as its factorization.

581521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 400, while the sum is 22.

The square root of 581521 is about 762.5752421893. The cubic root of 581521 is about 83.4683447006.

The spelling of 581521 in words is "five hundred eighty-one thousand, five hundred twenty-one".