121121222121021 has 4 divisors (see below), whose sum is σ = 161494962828032. Its totient is φ = 80747481414012.

The previous prime is 121121222121019. The next prime is 121121222121077. The reversal of 121121222121021 is 120121222121121.

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 not a de Polignac number, because 121121222121021 - 2¹ = 121121222121019 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 (121121222120021) 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, 20186870353501 + ... + 20186870353506.

It is an arithmetic number, because the mean of its divisors is an integer number (40373740707008).

Almost surely, 2^{121121222121021} is an apocalyptic number.

It is an amenable number.

121121222121021 is a deficient number, since it is larger than the sum of its proper divisors (40373740707011).

121121222121021 is an equidigital number, since it uses as much as digits as its factorization.

121121222121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40373740707010.

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 121121222121021 its reverse (120121222121121), we get a palindrome (241242444242142).

The spelling of 121121222121021 in words is "one hundred twenty-one trillion, one hundred twenty-one billion, two hundred twenty-two million, one hundred twenty-one thousand, twenty-one".