220121222121021 has 16 divisors (see below), whose sum is σ = 322035111611136. Its totient is φ = 132903379392576.

The previous prime is 220121222120999. The next prime is 220121222121049. The reversal of 220121222121021 is 120121222121022.

It is not a de Polignac number, because 220121222121021 - 2¹⁸ = 220121221858877 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220121222171021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53246544165 + ... + 53246548298.

It is an arithmetic number, because the mean of its divisors is an integer number (20127194475696).

Almost surely, 2^{220121222121021} is an apocalyptic number.

It is an amenable number.

220121222121021 is a deficient number, since it is larger than the sum of its proper divisors (101913889490115).

220121222121021 is a wasteful number, since it uses less digits than its factorization.

220121222121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106493092532.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 220121222121021 its reverse (120121222121022), we get a palindrome (340242444242043).

Subtracting from 220121222121021 its reverse (120121222121022), we obtain a palindrome (99999999999999).

The spelling of 220121222121021 in words is "two hundred twenty trillion, one hundred twenty-one billion, two hundred twenty-two million, one hundred twenty-one thousand, twenty-one".