221121120021121 has 4 divisors (see below), whose sum is σ = 221123170641492. Its totient is φ = 221119069400752.

The previous prime is 221121120021101. The next prime is 221121120021181. The reversal of 221121120021121 is 121120021121122.

It is a happy number.

221121120021121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 147014073004096 + 74107047017025 = 12124936^2 + 8608545^2 .

It is a cyclic number.

It is not a de Polignac number, because 221121120021121 - 2⁹ = 221121120020609 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221121120021101) 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, 1025148430 + ... + 1025364103.

It is an arithmetic number, because the mean of its divisors is an integer number (55280792660373).

Almost surely, 2^{221121120021121} is an apocalyptic number.

It is an amenable number.

221121120021121 is a deficient number, since it is larger than the sum of its proper divisors (2050620371).

221121120021121 is a wasteful number, since it uses less digits than its factorization.

221121120021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2050620370.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 221121120021121 its reverse (121120021121122), we get a palindrome (342241141142243).

The spelling of 221121120021121 in words is "two hundred twenty-one trillion, one hundred twenty-one billion, one hundred twenty million, twenty-one thousand, one hundred twenty-one".