210813 has 4 divisors (see below), whose sum is σ = 281088. Its totient is φ = 140540.

The previous prime is 210811. The next prime is 210823. The reversal of 210813 is 318012.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 210813 - 2¹ = 210811 is a prime.

It is a D-number.

210813 is a lucky number.

It is a plaindrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 210792 and 210801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210811) 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, 35133 + ... + 35138.

It is an arithmetic number, because the mean of its divisors is an integer number (70272).

2²¹⁰⁸¹³ is an apocalyptic number.

It is an amenable number.

210813 is a deficient number, since it is larger than the sum of its proper divisors (70275).

210813 is an equidigital number, since it uses as much as digits as its factorization.

210813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70274.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 210813 is about 459.1437683341. The cubic root of 210813 is about 59.5158256517.

Adding to 210813 its reverse (318012), we get a palindrome (528825).

The spelling of 210813 in words is "two hundred ten thousand, eight hundred thirteen".