12121111221 has 8 divisors (see below), whose sum is σ = 16277751840. Its totient is φ = 8022605712.

The previous prime is 12121111207. The next prime is 12121111243. The reversal of 12121111221 is 12211112121.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12121111221 - 2⁶ = 12121111157 is a prime.

It is a super-2 number, since 2×12121111221² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 12121111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12121111291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14533290 + ... + 14534123.

It is an arithmetic number, because the mean of its divisors is an integer number (2034718980).

Almost surely, 2^12121111221 is an apocalyptic number.

It is an amenable number.

12121111221 is a deficient number, since it is larger than the sum of its proper divisors (4156640619).

12121111221 is a wasteful number, since it uses less digits than its factorization.

12121111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29067555.

The product of its digits is 16, while the sum is 15.

Adding to 12121111221 its reverse (12211112121), we get a palindrome (24332223342).

The spelling of 12121111221 in words is "twelve billion, one hundred twenty-one million, one hundred eleven thousand, two hundred twenty-one".