521431 has 4 divisors (see below), whose sum is σ = 522952. Its totient is φ = 519912.

The previous prime is 521429. The next prime is 521447. The reversal of 521431 is 134125.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 521431 - 2¹ = 521429 is a prime.

It is a super-2 number, since 2×521431² = 543780575522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521401) 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, 25 + ... + 1021.

It is an arithmetic number, because the mean of its divisors is an integer number (130738).

2⁵²¹⁴³¹ is an apocalyptic number.

521431 is a deficient number, since it is larger than the sum of its proper divisors (1521).

521431 is an equidigital number, since it uses as much as digits as its factorization.

521431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1520.

The product of its digits is 120, while the sum is 16.

The square root of 521431 is about 722.1017933782. The cubic root of 521431 is about 80.4882124633.

Adding to 521431 its reverse (134125), we get a palindrome (655556).

The spelling of 521431 in words is "five hundred twenty-one thousand, four hundred thirty-one".