1212112221 has 8 divisors (see below), whose sum is σ = 1638288960. Its totient is φ = 797005152.

The previous prime is 1212112207. The next prime is 1212112229. The reversal of 1212112221 is 1222112121.

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

It is not a de Polignac number, because 1212112221 - 2²² = 1207917917 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1212112221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212112229) 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, 2767161 + ... + 2767598.

It is an arithmetic number, because the mean of its divisors is an integer number (204786120).

Almost surely, 2^1212112221 is an apocalyptic number.

It is an amenable number.

1212112221 is a deficient number, since it is larger than the sum of its proper divisors (426176739).

1212112221 is an equidigital number, since it uses as much as digits as its factorization.

1212112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5534835.

The product of its digits is 32, while the sum is 15.

The square root of 1212112221 is about 34815.4020657525. The cubic root of 1212112221 is about 1066.2219279525.

Adding to 1212112221 its reverse (1222112121), we get a palindrome (2434224342).

It can be divided in two parts, 12121 and 12221, that added together give a palindrome (24342).

The spelling of 1212112221 in words is "one billion, two hundred twelve million, one hundred twelve thousand, two hundred twenty-one".