12101222221 has 12 divisors (see below), whose sum is σ = 13450808700. Its totient is φ = 10877493440.

The previous prime is 12101222213. The next prime is 12101222249. The reversal of 12101222221 is 12222210121.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 6751908900 + 5349313321 = 82170^2 + 73139^2 .

It is not a de Polignac number, because 12101222221 - 2³ = 12101222213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12101222195 and 12101222204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12101222261) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 551086 + ... + 572623.

It is an arithmetic number, because the mean of its divisors is an integer number (1120900725).

Almost surely, 2^12101222221 is an apocalyptic number.

12101222221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12101222221 is a deficient number, since it is larger than the sum of its proper divisors (1349586479).

12101222221 is a wasteful number, since it uses less digits than its factorization.

12101222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1123820 (or 1123809 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 12101222221 its reverse (12222210121), we get a palindrome (24323432342).

The spelling of 12101222221 in words is "twelve billion, one hundred one million, two hundred twenty-two thousand, two hundred twenty-one".