521540440533513 has 6 divisors (see below), whose sum is σ = 753336191881754. Its totient is φ = 347693627022336.

The previous prime is 521540440533491. The next prime is 521540440533551. The reversal of 521540440533513 is 315335044045125.

521540440533513 is a `hidden beast` number, since 5 + 2 + 1 + 5 + 40 + 4 + 40 + 53 + 3 + 513 = 666.

It can be written as a sum of positive squares in only one way, i.e., 358576527037689 + 162963913495824 = 18936117^2 + 12765732^2 .

It is not a de Polignac number, because 521540440533513 - 2³⁰ = 521539366791689 is a prime.

It is a super-3 number, since 3×521540440533513³ (a number of 45 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521540440533583) 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 in 5 ways as a sum of consecutive naturals, for example, 28974468918520 + ... + 28974468918537.

Almost surely, 2^{521540440533513} is an apocalyptic number.

It is an amenable number.

521540440533513 is a deficient number, since it is larger than the sum of its proper divisors (231795751348241).

521540440533513 is a wasteful number, since it uses less digits than its factorization.

521540440533513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57948937837063 (or 57948937837060 counting only the distinct ones).

The product of its (nonzero) digits is 2160000, while the sum is 45.

Adding to 521540440533513 its reverse (315335044045125), we get a palindrome (836875484578638).

The spelling of 521540440533513 in words is "five hundred twenty-one trillion, five hundred forty billion, four hundred forty million, five hundred thirty-three thousand, five hundred thirteen".