221121200021121 has 24 divisors (see below), whose sum is σ = 319586403092840. Its totient is φ = 147326855360256.

The previous prime is 221121200021087. The next prime is 221121200021123. The reversal of 221121200021121 is 121120002121122.

221121200021121 is a `hidden beast` number, since 2 + 211 + 21 + 200 + 0 + 211 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 84551335232400 + 136569864788721 = 9195180^2 + 11686311^2 .

It is not a de Polignac number, because 221121200021121 - 2¹⁹ = 221121199496833 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221121200021094 and 221121200021103.

It is not an unprimeable number, because it can be changed into a prime (221121200021123) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 523602765 + ... + 524024901.

Almost surely, 2^{221121200021121} is an apocalyptic number.

It is an amenable number.

221121200021121 is a deficient number, since it is larger than the sum of its proper divisors (98465203071719).

221121200021121 is a wasteful number, since it uses less digits than its factorization.

221121200021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456465 (or 456462 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 221121200021121 its reverse (121120002121122), we get a palindrome (342241202142243).

The spelling of 221121200021121 in words is "two hundred twenty-one trillion, one hundred twenty-one billion, two hundred million, twenty-one thousand, one hundred twenty-one".