1221331023331 has 4 divisors (see below), whose sum is σ = 1221794881272. Its totient is φ = 1220867165392.

The previous prime is 1221331023313. The next prime is 1221331023371. The reversal of 1221331023331 is 1333201331221.

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

It is a cyclic number.

It is not a de Polignac number, because 1221331023331 - 2²⁷ = 1221196805603 is a prime.

It is a super-2 number, since 2×1221331023331² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1221331023296 and 1221331023305.

It is not an unprimeable number, because it can be changed into a prime (1221331023371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 231925021 + ... + 231930286.

It is an arithmetic number, because the mean of its divisors is an integer number (305448720318).

Almost surely, 2^{1221331023331} is an apocalyptic number.

1221331023331 is a deficient number, since it is larger than the sum of its proper divisors (463857941).

1221331023331 is an equidigital number, since it uses as much as digits as its factorization.

1221331023331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 463857940.

The product of its (nonzero) digits is 1944, while the sum is 25.

Adding to 1221331023331 its reverse (1333201331221), we get a palindrome (2554532354552).

The spelling of 1221331023331 in words is "one trillion, two hundred twenty-one billion, three hundred thirty-one million, twenty-three thousand, three hundred thirty-one".