10000001221 has 16 divisors (see below), whose sum is σ = 11515730688. Its totient is φ = 8506310400.

The previous prime is 10000001159. The next prime is 10000001251. The reversal of 10000001221 is 12210000001.

It is not a de Polignac number, because 10000001221 - 2²⁷ = 9865783493 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (7).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10000001251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 484176 + ... + 504406.

It is an arithmetic number, because the mean of its divisors is an integer number (719733168).

Almost surely, 2^10000001221 is an apocalyptic number.

It is an amenable number.

10000001221 is a deficient number, since it is larger than the sum of its proper divisors (1515729467).

10000001221 is a wasteful number, since it uses less digits than its factorization.

10000001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20772.

The product of its (nonzero) digits is 4, while the sum is 7.

Adding to 10000001221 its reverse (12210000001), we get a palindrome (22210001222).

The spelling of 10000001221 in words is "ten billion, one thousand, two hundred twenty-one".