521537 has 2 divisors, whose sum is σ = 521538. Its totient is φ = 521536.

The previous prime is 521533. The next prime is 521539. The reversal of 521537 is 735125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 495616 + 25921 = 704^2 + 161^2 .

It is a cyclic number.

It is not a de Polignac number, because 521537 - 2² = 521533 is a prime.

Together with 521539, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (521533) 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, 260768 + 260769.

It is an arithmetic number, because the mean of its divisors is an integer number (260769).

2⁵²¹⁵³⁷ is an apocalyptic number.

It is an amenable number.

521537 is a deficient number, since it is larger than the sum of its proper divisors (1).

521537 is an equidigital number, since it uses as much as digits as its factorization.

521537 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1050, while the sum is 23.

The square root of 521537 is about 722.1751865026. The cubic root of 521537 is about 80.4936661555.

The spelling of 521537 in words is "five hundred twenty-one thousand, five hundred thirty-seven".