210001220 has 96 divisors (see below), whose sum is σ = 523950336. Its totient is φ = 69696000.

The previous prime is 210001219. The next prime is 210001271. The reversal of 210001220 is 22100012.

It is a junction number, because it is equal to n+sod(n) for n = 210001198 and 210001207.

It is an unprimeable 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 31 ways as a sum of consecutive naturals, for example, 288497 + ... + 289223.

It is an arithmetic number, because the mean of its divisors is an integer number (5457816).

Almost surely, 2^210001220 is an apocalyptic number.

210001220 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 210001220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261975168).

210001220 is an abundant number, since it is smaller than the sum of its proper divisors (313949116).

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

210001220 is a wasteful number, since it uses less digits than its factorization.

210001220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 861 (or 859 counting only the distinct ones).

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

The square root of 210001220 is about 14491.4188401274. The cubic root of 210001220 is about 594.3933463193.

Adding to 210001220 its reverse (22100012), we get a palindrome (232101232).

The spelling of 210001220 in words is "two hundred ten million, one thousand, two hundred twenty".