2220021 has 8 divisors (see below), whose sum is σ = 3288960. Its totient is φ = 1479996.

The previous prime is 2220007. The next prime is 2220041. The reversal of 2220021 is 1200222.

It is not a de Polignac number, because 2220021 - 2¹⁴ = 2203637 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 2219985 and 2220012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2220041) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 41085 + ... + 41138.

It is an arithmetic number, because the mean of its divisors is an integer number (411120).

2^2220021 is an apocalyptic number.

It is an amenable number.

2220021 is a deficient number, since it is larger than the sum of its proper divisors (1068939).

2220021 is an equidigital number, since it uses as much as digits as its factorization.

2220021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82232 (or 82226 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 9.

The square root of 2220021 is about 1489.9734896970. The cubic root of 2220021 is about 130.4524863361.

Adding to 2220021 its reverse (1200222), we get a palindrome (3420243).

The spelling of 2220021 in words is "two million, two hundred twenty thousand, twenty-one".