521531 has 4 divisors (see below), whose sum is σ = 549000. Its totient is φ = 494064.

The previous prime is 521527. The next prime is 521533. The reversal of 521531 is 135125.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 521531 - 2² = 521527 is a prime.

It is a super-2 number, since 2×521531² = 543989167922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (521533) 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, 13706 + ... + 13743.

It is an arithmetic number, because the mean of its divisors is an integer number (137250).

2⁵²¹⁵³¹ is an apocalyptic number.

521531 is a deficient number, since it is larger than the sum of its proper divisors (27469).

521531 is a wasteful number, since it uses less digits than its factorization.

521531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27468.

The product of its digits is 150, while the sum is 17.

The square root of 521531 is about 722.1710323739. The cubic root of 521531 is about 80.4933574756.

Adding to 521531 its reverse (135125), we get a palindrome (656656).

The spelling of 521531 in words is "five hundred twenty-one thousand, five hundred thirty-one".