1000221121221 has 16 divisors (see below), whose sum is σ = 1549132480128. Its totient is φ = 562185172800.

The previous prime is 1000221121189. The next prime is 1000221121243. The reversal of 1000221121221 is 1221211220001.

1000221121221 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1000221121221 - 2⁵ = 1000221121189 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1000221121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000221121261) 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, 390405090 + ... + 390407651.

It is an arithmetic number, because the mean of its divisors is an integer number (96820780008).

Almost surely, 2^{1000221121221} is an apocalyptic number.

It is an amenable number.

1000221121221 is a deficient number, since it is larger than the sum of its proper divisors (548911358907).

1000221121221 is an equidigital number, since it uses as much as digits as its factorization.

1000221121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780812812.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1000221121221 its reverse (1221211220001), we get a palindrome (2221432341222).

The spelling of 1000221121221 in words is "one trillion, two hundred twenty-one million, one hundred twenty-one thousand, two hundred twenty-one".