210221320 has 128 divisors (see below), whose sum is σ = 538876800. Its totient is φ = 73322496.

The previous prime is 210221279. The next prime is 210221327. The reversal of 210221320 is 23122012.

It is a self number, because there is not a number n which added to its sum of digits gives 210221320.

It is not an unprimeable number, because it can be changed into a prime (210221327) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 684607 + ... + 684913.

It is an arithmetic number, because the mean of its divisors is an integer number (4209975).

Almost surely, 2^210221320 is an apocalyptic number.

210221320 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 210221320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (269438400).

210221320 is an abundant number, since it is smaller than the sum of its proper divisors (328655480).

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

210221320 is a wasteful number, since it uses less digits than its factorization.

210221320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407 (or 403 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 210221320 is about 14499.0110007545. The cubic root of 210221320 is about 594.6009328853.

Adding to 210221320 its reverse (23122012), we get a palindrome (233343332).

The spelling of 210221320 in words is "two hundred ten million, two hundred twenty-one thousand, three hundred twenty".