523821 has 8 divisors (see below), whose sum is σ = 739584. Its totient is φ = 328640.

The previous prime is 523801. The next prime is 523829. The reversal of 523821 is 128325.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-523821 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (523829) 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, 5085 + ... + 5186.

It is an arithmetic number, because the mean of its divisors is an integer number (92448).

2⁵²³⁸²¹ is an apocalyptic number.

523821 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

523821 is a deficient number, since it is larger than the sum of its proper divisors (215763).

523821 is a wasteful number, since it uses less digits than its factorization.

523821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10291.

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

The square root of 523821 is about 723.7547927302. The cubic root of 523821 is about 80.6109987104.

The spelling of 523821 in words is "five hundred twenty-three thousand, eight hundred twenty-one".