221210021212221 has 16 divisors (see below), whose sum is σ = 307771625885184. Its totient is φ = 141060930406704.

The previous prime is 221210021212211. The next prime is 221210021212241. The reversal of 221210021212221 is 122212120012122.

It is not a de Polignac number, because 221210021212221 - 2⁶ = 221210021212157 is a prime.

It is a super-2 number, since 2×221210021212221² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221210021212211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12786430 + ... + 24615296.

It is an arithmetic number, because the mean of its divisors is an integer number (19235726617824).

Almost surely, 2^{221210021212221} is an apocalyptic number.

It is an amenable number.

221210021212221 is a deficient number, since it is larger than the sum of its proper divisors (86561604672963).

221210021212221 is a wasteful number, since it uses less digits than its factorization.

221210021212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12099920.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 221210021212221 its reverse (122212120012122), we get a palindrome (343422141224343).

The spelling of 221210021212221 in words is "two hundred twenty-one trillion, two hundred ten billion, twenty-one million, two hundred twelve thousand, two hundred twenty-one".