1221321133321 has 4 divisors (see below), whose sum is σ = 1221333379200. Its totient is φ = 1221308887444.

The previous prime is 1221321133301. The next prime is 1221321133423. The reversal of 1221321133321 is 1233311231221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1221321133321 - 2¹⁵ = 1221321100553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221321133301) 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, 5972101 + ... + 6173218.

It is an arithmetic number, because the mean of its divisors is an integer number (305333344800).

Almost surely, 2^{1221321133321} is an apocalyptic number.

It is an amenable number.

1221321133321 is a deficient number, since it is larger than the sum of its proper divisors (12245879).

1221321133321 is a wasteful number, since it uses less digits than its factorization.

1221321133321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12245878.

The product of its digits is 1296, while the sum is 25.

Adding to 1221321133321 its reverse (1233311231221), we get a palindrome (2454632364542).

The spelling of 1221321133321 in words is "one trillion, two hundred twenty-one billion, three hundred twenty-one million, one hundred thirty-three thousand, three hundred twenty-one".