521521321393 has 2 divisors, whose sum is σ = 521521321394. Its totient is φ = 521521321392.

The previous prime is 521521321313. The next prime is 521521321459. The reversal of 521521321393 is 393123125125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 369789258609 + 151732062784 = 608103^2 + 389528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521521321393 is a prime.

It is not a weakly prime, because it can be changed into another prime (521521321313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 260760660696 + 260760660697.

It is an arithmetic number, because the mean of its divisors is an integer number (260760660697).

Almost surely, 2^521521321393 is an apocalyptic number.

It is an amenable number.

521521321393 is a deficient number, since it is larger than the sum of its proper divisors (1).

521521321393 is an equidigital number, since it uses as much as digits as its factorization.

521521321393 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48600, while the sum is 37.

The spelling of 521521321393 in words is "five hundred twenty-one billion, five hundred twenty-one million, three hundred twenty-one thousand, three hundred ninety-three".