221001020112121 has 4 divisors (see below), whose sum is σ = 221001678109044. Its totient is φ = 221000362115200.

The previous prime is 221001020112097. The next prime is 221001020112193. The reversal of 221001020112121 is 121211020100122.

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 124125446145600 + 96875573966521 = 11141160^2 + 9842539^2 .

It is a cyclic number.

It is not a de Polignac number, because 221001020112121 - 2²¹ = 221001018014969 is a prime.

It is a super-2 number, since 2×221001020112121² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221001020112095 and 221001020112104.

It is not an unprimeable number, because it can be changed into a prime (221001020112721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 328494400 + ... + 329166481.

It is an arithmetic number, because the mean of its divisors is an integer number (55250419527261).

Almost surely, 2^{221001020112121} is an apocalyptic number.

It is an amenable number.

221001020112121 is a deficient number, since it is larger than the sum of its proper divisors (657996923).

221001020112121 is an equidigital number, since it uses as much as digits as its factorization.

221001020112121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657996922.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 221001020112121 its reverse (121211020100122), we get a palindrome (342212040212243).

The spelling of 221001020112121 in words is "two hundred twenty-one trillion, one billion, twenty million, one hundred twelve thousand, one hundred twenty-one".