210823 has 2 divisors, whose sum is σ = 210824. Its totient is φ = 210822.

The previous prime is 210811. The next prime is 210827. The reversal of 210823 is 328012.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210823 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 210797 and 210806.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105411 + 105412.

It is an arithmetic number, because the mean of its divisors is an integer number (105412).

2²¹⁰⁸²³ is an apocalyptic number.

210823 is a deficient number, since it is larger than the sum of its proper divisors (1).

210823 is an equidigital number, since it uses as much as digits as its factorization.

210823 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 210823 is about 459.1546580402. The cubic root of 210823 is about 59.5167666893.

Adding to 210823 its reverse (328012), we get a palindrome (538835).

It can be divided in two parts, 2108 and 23, that multiplied together give a palindrome (48484).

The spelling of 210823 in words is "two hundred ten thousand, eight hundred twenty-three".