1001220111121 has 4 divisors (see below), whose sum is σ = 1001331975744. Its totient is φ = 1001108246500.

The previous prime is 1001220111119. The next prime is 1001220111127. The reversal of 1001220111121 is 1211110221001.

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 1001220111121 - 2¹ = 1001220111119 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1001220111127) 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, 55918885 + ... + 55936786.

It is an arithmetic number, because the mean of its divisors is an integer number (250332993936).

Almost surely, 2^{1001220111121} is an apocalyptic number.

It is an amenable number.

1001220111121 is a deficient number, since it is larger than the sum of its proper divisors (111864623).

1001220111121 is an equidigital number, since it uses as much as digits as its factorization.

1001220111121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111864622.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1001220111121 its reverse (1211110221001), we get a palindrome (2212330332122).

The spelling of 1001220111121 in words is "one trillion, one billion, two hundred twenty million, one hundred eleven thousand, one hundred twenty-one".