20002221 has 10 divisors (see below), whose sum is σ = 29879982. Its totient is φ = 13334760.

The previous prime is 20002201. The next prime is 20002261. The reversal of 20002221 is 12220002.

It can be written as a sum of positive squares in only one way, i.e., 18275625 + 1726596 = 4275^2 + 1314^2 .

It is not a de Polignac number, because 20002221 - 2⁵ = 20002189 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20002201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 123390 + ... + 123551.

Almost surely, 2^20002221 is an apocalyptic number.

It is an amenable number.

20002221 is a deficient number, since it is larger than the sum of its proper divisors (9877761).

20002221 is an equidigital number, since it uses as much as digits as its factorization.

20002221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246953 (or 246944 counting only the distinct ones).

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

The square root of 20002221 is about 4472.3842634550. The cubic root of 20002221 is about 271.4518091568.

Adding to 20002221 its reverse (12220002), we get a palindrome (32222223).

The spelling of 20002221 in words is "twenty million, two thousand, two hundred twenty-one".