521823 has 12 divisors (see below), whose sum is σ = 722904. Its totient is φ = 334800.

The previous prime is 521819. The next prime is 521831. The reversal of 521823 is 328125.

It is not a de Polignac number, because 521823 - 2² = 521819 is a prime.

It is a Smith number, since the sum of its digits (21) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 521823.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521813) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2793 + ... + 2973.

It is an arithmetic number, because the mean of its divisors is an integer number (60242).

2⁵²¹⁸²³ is an apocalyptic number.

521823 is a deficient number, since it is larger than the sum of its proper divisors (201081).

521823 is a wasteful number, since it uses less digits than its factorization.

521823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246 (or 215 counting only the distinct ones).

The product of its digits is 480, while the sum is 21.

The square root of 521823 is about 722.3731722593. The cubic root of 521823 is about 80.5083771486.

Adding to 521823 its reverse (328125), we get a palindrome (849948).

The spelling of 521823 in words is "five hundred twenty-one thousand, eight hundred twenty-three".