121121211022221 has 4 divisors (see below), whose sum is σ = 161494948029632. Its totient is φ = 80747474014812.

The previous prime is 121121211022213. The next prime is 121121211022243. The reversal of 121121211022221 is 122220112121121.

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 121121211022221 - 2³ = 121121211022213 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 (121121211022291) 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, 20186868503701 + ... + 20186868503706.

It is an arithmetic number, because the mean of its divisors is an integer number (40373737007408).

Almost surely, 2^{121121211022221} is an apocalyptic number.

It is an amenable number.

121121211022221 is a deficient number, since it is larger than the sum of its proper divisors (40373737007411).

121121211022221 is an equidigital number, since it uses as much as digits as its factorization.

121121211022221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40373737007410.

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

Adding to 121121211022221 its reverse (122220112121121), we get a palindrome (243341323143342).

The spelling of 121121211022221 in words is "one hundred twenty-one trillion, one hundred twenty-one billion, two hundred eleven million, twenty-two thousand, two hundred twenty-one".