210900 has 72 divisors (see below), whose sum is σ = 659680. Its totient is φ = 51840.

The previous prime is 210869. The next prime is 210901. The reversal of 210900 is 9012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (210901) by changing a digit.

210900 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 in 23 ways as a sum of consecutive naturals, for example, 5682 + ... + 5718.

2²¹⁰⁹⁰⁰ is an apocalyptic number.

210900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 210900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329840).

210900 is an abundant number, since it is smaller than the sum of its proper divisors (448780).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

210900 is a wasteful number, since it uses less digits than its factorization.

210900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 12.

The square root of 210900 is about 459.2385001282. The cubic root of 210900 is about 59.5240116819.

Adding to 210900 its reverse (9012), we get a palindrome (219912).

The spelling of 210900 in words is "two hundred ten thousand, nine hundred".