823531 has 8 divisors (see below), whose sum is σ = 879984. Its totient is φ = 768000.

The previous prime is 823519. The next prime is 823541. The reversal of 823531 is 135328.

823531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a 11-Lehmer number, since φ(823531) divides (823531-1)¹¹.

It is a cyclic number.

It is not a de Polignac number, because 823531 - 2⁵ = 823499 is a prime.

It is a super-2 number, since 2×823531² = 1356406615922, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (823541) 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, 3156 + ... + 3406.

It is an arithmetic number, because the mean of its divisors is an integer number (109998).

2⁸²³⁵³¹ is an apocalyptic number.

823531 is a deficient number, since it is larger than the sum of its proper divisors (56453).

823531 is a wasteful number, since it uses less digits than its factorization.

823531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 461.

The product of its digits is 720, while the sum is 22.

The square root of 823531 is about 907.4860880476. The cubic root of 823531 is about 93.7331726835.

Adding to 823531 its reverse (135328), we get a palindrome (958859).

The spelling of 823531 in words is "eight hundred twenty-three thousand, five hundred thirty-one".