221012111221 has 16 divisors (see below), whose sum is σ = 251620629120. Its totient is φ = 192158686720.

The previous prime is 221012111189. The next prime is 221012111251. The reversal of 221012111221 is 122111210122.

It is not a de Polignac number, because 221012111221 - 2⁵ = 221012111189 is a prime.

It is a super-2 number, since 2×221012111221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221012111195 and 221012111204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221012111251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1971741 + ... + 2080813.

It is an arithmetic number, because the mean of its divisors is an integer number (15726289320).

Almost surely, 2^221012111221 is an apocalyptic number.

It is an amenable number.

221012111221 is a deficient number, since it is larger than the sum of its proper divisors (30608517899).

221012111221 is a wasteful number, since it uses less digits than its factorization.

221012111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117116.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 221012111221 its reverse (122111210122), we get a palindrome (343123321343).

It can be divided in two parts, 221012 and 111221, that added together give a palindrome (332233).

The spelling of 221012111221 in words is "two hundred twenty-one billion, twelve million, one hundred eleven thousand, two hundred twenty-one".