221011022121021 has 54 divisors (see below), whose sum is σ = 366817888818654. Its totient is φ = 128122331330400.

The previous prime is 221011022120983. The next prime is 221011022121049. The reversal of 221011022121021 is 120121220110122.

221011022121021 is a `hidden beast` number, since 2 + 210 + 1 + 1 + 0 + 221 + 210 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 199193846096025 + 21817176024996 = 14113605^2 + 4670886^2 .

It is not a de Polignac number, because 221011022121021 - 2⁶ = 221011022120957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221011022120985 and 221011022121003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221011022121061) by changing a digit.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 191246790 + ... + 192398951.

Almost surely, 2^{221011022121021} is an apocalyptic number.

It is an amenable number.

221011022121021 is a deficient number, since it is larger than the sum of its proper divisors (145806866697633).

221011022121021 is a wasteful number, since it uses less digits than its factorization.

221011022121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 383645815 (or 383645778 counting only the distinct ones).

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

Adding to 221011022121021 its reverse (120121220110122), we get a palindrome (341132242231143).

The spelling of 221011022121021 in words is "two hundred twenty-one trillion, eleven billion, twenty-two million, one hundred twenty-one thousand, twenty-one".