1221321133211 has 4 divisors (see below), whose sum is σ = 1221673813872. Its totient is φ = 1220968452552.

The previous prime is 1221321133139. The next prime is 1221321133213. The reversal of 1221321133211 is 1123311231221.

It is a happy number.

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-1221321133211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221321133213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176335136 + ... + 176342061.

It is an arithmetic number, because the mean of its divisors is an integer number (305418453468).

Almost surely, 2^{1221321133211} is an apocalyptic number.

1221321133211 is a deficient number, since it is larger than the sum of its proper divisors (352680661).

1221321133211 is an equidigital number, since it uses as much as digits as its factorization.

1221321133211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 352680660.

The product of its digits is 432, while the sum is 23.

Adding to 1221321133211 its reverse (1123311231221), we get a palindrome (2344632364432).

The spelling of 1221321133211 in words is "one trillion, two hundred twenty-one billion, three hundred twenty-one million, one hundred thirty-three thousand, two hundred eleven".