521521521 has 8 divisors (see below), whose sum is σ = 696698784. Its totient is φ = 347012640.

The previous prime is 521521499. The next prime is 521521523. The reversal of 521521521 is 125125125.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 521521521 - 2⁶ = 521521457 is a prime.

521521521 is a modest number, since divided by 521521 gives 521 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 521521491 and 521521500.

It is not an unprimeable number, because it can be changed into a prime (521521523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 165271 + ... + 168396.

It is an arithmetic number, because the mean of its divisors is an integer number (87087348).

Almost surely, 2^521521521 is an apocalyptic number.

It is an amenable number.

521521521 is a deficient number, since it is larger than the sum of its proper divisors (175177263).

521521521 is a wasteful number, since it uses less digits than its factorization.

521521521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 334191.

The product of its digits is 1000, while the sum is 24.

The square root of 521521521 is about 22836.8456884921. The cubic root of 521521521 is about 804.9286980814.

Adding to 521521521 its reverse (125125125), we get a palindrome (646646646).

The spelling of 521521521 in words is "five hundred twenty-one million, five hundred twenty-one thousand, five hundred twenty-one".