521540013 has 4 divisors (see below), whose sum is σ = 695386688. Its totient is φ = 347693340.

The previous prime is 521540003. The next prime is 521540023. The reversal of 521540013 is 310045125.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (521540003) and next prime (521540023).

It is not a de Polignac number, because 521540013 - 2⁸ = 521539757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521540003) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 86923333 + ... + 86923338.

It is an arithmetic number, because the mean of its divisors is an integer number (173846672).

Almost surely, 2^521540013 is an apocalyptic number.

It is an amenable number.

521540013 is a deficient number, since it is larger than the sum of its proper divisors (173846675).

521540013 is a wasteful number, since it uses less digits than its factorization.

521540013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173846674.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 521540013 is about 22837.2505569300. The cubic root of 521540013 is about 804.9382116329.

Adding to 521540013 its reverse (310045125), we get a palindrome (831585138).

The spelling of 521540013 in words is "five hundred twenty-one million, five hundred forty thousand, thirteen".