521423521 has 2 divisors, whose sum is σ = 521423522. Its totient is φ = 521423520.

The previous prime is 521423491. The next prime is 521423531. The reversal of 521423521 is 125324125.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 311028496 + 210395025 = 17636^2 + 14505^2 .

It is a cyclic number.

It is not a de Polignac number, because 521423521 - 2⁹ = 521423009 is a prime.

It is not a weakly prime, because it can be changed into another prime (521423531) 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, 260711760 + 260711761.

It is an arithmetic number, because the mean of its divisors is an integer number (260711761).

Almost surely, 2^521423521 is an apocalyptic number.

It is an amenable number.

521423521 is a deficient number, since it is larger than the sum of its proper divisors (1).

521423521 is an equidigital number, since it uses as much as digits as its factorization.

521423521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2400, while the sum is 25.

The square root of 521423521 is about 22834.6999323398. The cubic root of 521423521 is about 804.8782764140.

Adding to 521423521 its reverse (125324125), we get a palindrome (646747646).

The spelling of 521423521 in words is "five hundred twenty-one million, four hundred twenty-three thousand, five hundred twenty-one".