10221220 has 12 divisors (see below), whose sum is σ = 21464604. Its totient is φ = 4088480.

The previous prime is 10221203. The next prime is 10221247. The reversal of 10221220 is 2212201.

It can be written as a sum of positive squares in 2 ways, for example, as 1028196 + 9193024 = 1014^2 + 3032^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a junction number, because it is equal to n+sod(n) for n = 10221197 and 10221206.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 255511 + ... + 255550.

It is an arithmetic number, because the mean of its divisors is an integer number (1788717).

Almost surely, 2^10221220 is an apocalyptic number.

10221220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

10221220 is an abundant number, since it is smaller than the sum of its proper divisors (11243384).

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

10221220 is a wasteful number, since it uses less digits than its factorization.

10221220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511070 (or 511068 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 10221220 is about 3197.0642783654. The cubic root of 10221220 is about 217.0205761032.

Adding to 10221220 its reverse (2212201), we get a palindrome (12433421).

The spelling of 10221220 in words is "ten million, two hundred twenty-one thousand, two hundred twenty".