10021220 has 72 divisors (see below), whose sum is σ = 23930424. Its totient is φ = 3520000.

The previous prime is 10021217. The next prime is 10021237. The reversal of 10021220 is 2212001.

10021220 = 293² + 294² + ... + 380².

It can be written as a sum of positive squares in 4 ways, for example, as 1069156 + 8952064 = 1034^2 + 2992^2 .

It is a junction number, because it is equal to n+sod(n) for n = 10021198 and 10021207.

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 23 ways as a sum of consecutive naturals, for example, 99170 + ... + 99270.

It is an arithmetic number, because the mean of its divisors is an integer number (332367).

Almost surely, 2^10021220 is an apocalyptic number.

10021220 is a gapful number since it is divisible by the number (10) 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 10021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11965212).

10021220 is an abundant number, since it is smaller than the sum of its proper divisors (13909204).

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

10021220 is a wasteful number, since it uses less digits than its factorization.

10021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173 (or 160 counting only the distinct ones).

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

The square root of 10021220 is about 3165.6310587306. The cubic root of 10021220 is about 215.5957516864.

Adding to 10021220 its reverse (2212001), we get a palindrome (12233221).

It can be divided in two parts, 1002 and 1220, that added together give a palindrome (2222).

The spelling of 10021220 in words is "ten million, twenty-one thousand, two hundred twenty".