221212100021121 has 32 divisors (see below), whose sum is σ = 359075703907200. Its totient is φ = 133482489848640.

The previous prime is 221212100021053. The next prime is 221212100021131. The reversal of 221212100021121 is 121120001212122.

221212100021121 is a `hidden beast` number, since 221 + 2 + 1 + 210 + 0 + 0 + 211 + 21 = 666.

It is not a de Polignac number, because 221212100021121 - 2⁹ = 221212100020609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221212100021094 and 221212100021103.

It is not an unprimeable number, because it can be changed into a prime (221212100021131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1626180646 + ... + 1626316671.

It is an arithmetic number, because the mean of its divisors is an integer number (11221115747100).

Almost surely, 2^{221212100021121} is an apocalyptic number.

It is an amenable number.

221212100021121 is a deficient number, since it is larger than the sum of its proper divisors (137863603886079).

221212100021121 is a wasteful number, since it uses less digits than its factorization.

221212100021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3252497566 (or 3252497560 counting only the distinct ones).

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

Adding to 221212100021121 its reverse (121120001212122), we get a palindrome (342332101233243).

The spelling of 221212100021121 in words is "two hundred twenty-one trillion, two hundred twelve billion, one hundred million, twenty-one thousand, one hundred twenty-one".