10001220221 has 4 divisors (see below), whose sum is σ = 10006396092. Its totient is φ = 9996044352.

The previous prime is 10001220197. The next prime is 10001220223. The reversal of 10001220221 is 12202210001.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6621076900 + 3380143321 = 81370^2 + 58139^2 .

It is a cyclic number.

It is not a de Polignac number, because 10001220221 - 2³⁰ = 8927478397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10001220223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2585036 + ... + 2588901.

It is an arithmetic number, because the mean of its divisors is an integer number (2501599023).

Almost surely, 2^10001220221 is an apocalyptic number.

It is an amenable number.

10001220221 is a deficient number, since it is larger than the sum of its proper divisors (5175871).

10001220221 is an equidigital number, since it uses as much as digits as its factorization.

10001220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5175870.

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 10001220221 its reverse (12202210001), we get a palindrome (22203430222).

It can be divided in two parts, 1000 and 1220221, that added together give a palindrome (1221221).

The spelling of 10001220221 in words is "ten billion, one million, two hundred twenty thousand, two hundred twenty-one".