2221201220121 has 12 divisors (see below), whose sum is σ = 3455201898148. Its totient is φ = 1366893058464.

The previous prime is 2221201220081. The next prime is 2221201220129. The reversal of 2221201220121 is 1210221021222.

It is a happy number.

2221201220121 is a `hidden beast` number, since 2 + 221 + 201 + 220 + 1 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 622142337600 + 1599058882521 = 788760^2 + 1264539^2 .

It is not a de Polignac number, because 2221201220121 - 2²³ = 2221192831513 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2221201220094 and 2221201220103.

It is not an unprimeable number, because it can be changed into a prime (2221201220129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9492312790 + ... + 9492313023.

Almost surely, 2^{2221201220121} is an apocalyptic number.

It is an amenable number.

2221201220121 is a deficient number, since it is larger than the sum of its proper divisors (1234000678027).

2221201220121 is a wasteful number, since it uses less digits than its factorization.

2221201220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18984625832 (or 18984625829 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 2221201220121 its reverse (1210221021222), we get a palindrome (3431422241343).

The spelling of 2221201220121 in words is "two trillion, two hundred twenty-one billion, two hundred one million, two hundred twenty thousand, one hundred twenty-one".