1001221112121 has 4 divisors (see below), whose sum is σ = 1334961482832. Its totient is φ = 667480741412.

The previous prime is 1001221112107. The next prime is 1001221112141. The reversal of 1001221112121 is 1212111221001.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1001221112121 - 2¹⁷ = 1001220981049 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1001221112121.

It is not an unprimeable number, because it can be changed into a prime (1001221112141) 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, 166870185351 + ... + 166870185356.

It is an arithmetic number, because the mean of its divisors is an integer number (333740370708).

Almost surely, 2^{1001221112121} is an apocalyptic number.

It is an amenable number.

1001221112121 is a deficient number, since it is larger than the sum of its proper divisors (333740370711).

1001221112121 is an equidigital number, since it uses as much as digits as its factorization.

1001221112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333740370710.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1001221112121 its reverse (1212111221001), we get a palindrome (2213332333122).

The spelling of 1001221112121 in words is "one trillion, one billion, two hundred twenty-one million, one hundred twelve thousand, one hundred twenty-one".