210221000 has 128 divisors (see below), whose sum is σ = 555984000. Its totient is φ = 73696000.

The previous prime is 210220999. The next prime is 210221003. The reversal of 210221000 is 122012.

It is a Cunningham number, because it is equal to 14499²-1.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is not an unprimeable number, because it can be changed into a prime (210221003) 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, 318671 + ... + 319329.

It is an arithmetic number, because the mean of its divisors is an integer number (4343625).

Almost surely, 2^210221000 is an apocalyptic number.

210221000 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 210221000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (277992000).

210221000 is an abundant number, since it is smaller than the sum of its proper divisors (345763000).

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

210221000 is a wasteful number, since it uses less digits than its factorization.

210221000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720 (or 706 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 210221000 is about 14498.9999655149. Note that the first 4 decimals coincide. The cubic root of 210221000 is about 594.6006311836.

Adding to 210221000 its reverse (122012), we get a palindrome (210343012).

It can be divided in two parts, 21022 and 1000, that added together give a palindrome (22022).

The spelling of 210221000 in words is "two hundred ten million, two hundred twenty-one thousand".