1211122122221 has 8 divisors (see below), whose sum is σ = 1322798904000. Its totient is φ = 1099707802240.

The previous prime is 1211122122169. The next prime is 1211122122239. The reversal of 1211122122221 is 1222212211121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211122122221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1211122122193 and 1211122122202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1214122122221) 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, 65605796 + ... + 65624253.

It is an arithmetic number, because the mean of its divisors is an integer number (165349863000).

Almost surely, 2^{1211122122221} is an apocalyptic number.

1211122122221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211122122221 is a deficient number, since it is larger than the sum of its proper divisors (111676781779).

1211122122221 is a wasteful number, since it uses less digits than its factorization.

1211122122221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131230899.

The product of its digits is 128, while the sum is 20.

Adding to 1211122122221 its reverse (1222212211121), we get a palindrome (2433334333342).

The spelling of 1211122122221 in words is "one trillion, two hundred eleven billion, one hundred twenty-two million, one hundred twenty-two thousand, two hundred twenty-one".