1221131013211 has 4 divisors (see below), whose sum is σ = 1221136979800. Its totient is φ = 1221125046624.

The previous prime is 1221131013197. The next prime is 1221131013233. The reversal of 1221131013211 is 1123101311221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221131013211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221131013511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2664981 + ... + 3089398.

It is an arithmetic number, because the mean of its divisors is an integer number (305284244950).

Almost surely, 2^{1221131013211} is an apocalyptic number.

1221131013211 is a deficient number, since it is larger than the sum of its proper divisors (5966589).

1221131013211 is an equidigital number, since it uses as much as digits as its factorization.

1221131013211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5966588.

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 1221131013211 its reverse (1123101311221), we get a palindrome (2344232324432).

The spelling of 1221131013211 in words is "one trillion, two hundred twenty-one billion, one hundred thirty-one million, thirteen thousand, two hundred eleven".