521513421 has 16 divisors (see below), whose sum is σ = 816916800. Its totient is φ = 291755520.

The previous prime is 521513393. The next prime is 521513429. The reversal of 521513421 is 124315125.

It is a happy number.

It is not a de Polignac number, because 521513421 - 2¹⁵ = 521480653 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 521513391 and 521513400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521513429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 607396 + ... + 608253.

It is an arithmetic number, because the mean of its divisors is an integer number (51057300).

Almost surely, 2^521513421 is an apocalyptic number.

It is an amenable number.

521513421 is a deficient number, since it is larger than the sum of its proper divisors (295403379).

521513421 is a wasteful number, since it uses less digits than its factorization.

521513421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1215676.

The product of its digits is 1200, while the sum is 24.

The square root of 521513421 is about 22836.6683428209. The cubic root of 521513421 is about 804.9245308157.

Adding to 521513421 its reverse (124315125), we get a palindrome (645828546).

The spelling of 521513421 in words is "five hundred twenty-one million, five hundred thirteen thousand, four hundred twenty-one".