521863 has 4 divisors (see below), whose sum is σ = 529720. Its totient is φ = 514008.

The previous prime is 521861. The next prime is 521869. The reversal of 521863 is 368125.

It is a happy number.

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 521863 - 2¹ = 521861 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 (521861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3828 + ... + 3961.

It is an arithmetic number, because the mean of its divisors is an integer number (132430).

2⁵²¹⁸⁶³ is an apocalyptic number.

521863 is a deficient number, since it is larger than the sum of its proper divisors (7857).

521863 is an equidigital number, since it uses as much as digits as its factorization.

521863 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7856.

The product of its digits is 1440, while the sum is 25.

The square root of 521863 is about 722.4008582498. The cubic root of 521863 is about 80.5104342017.

Adding to 521863 its reverse (368125), we get a palindrome (889988).

The spelling of 521863 in words is "five hundred twenty-one thousand, eight hundred sixty-three".