1221231022311 has 4 divisors (see below), whose sum is σ = 1628308029752. Its totient is φ = 814154014872.

The previous prime is 1221231022289. The next prime is 1221231022369. The reversal of 1221231022311 is 1132201321221.

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

It is not a de Polignac number, because 1221231022311 - 2¹⁰ = 1221231021287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221231022511) 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, 203538503716 + ... + 203538503721.

It is an arithmetic number, because the mean of its divisors is an integer number (407077007438).

Almost surely, 2^{1221231022311} is an apocalyptic number.

1221231022311 is a deficient number, since it is larger than the sum of its proper divisors (407077007441).

1221231022311 is an equidigital number, since it uses as much as digits as its factorization.

1221231022311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 407077007440.

The product of its (nonzero) digits is 288, while the sum is 21.

Adding to 1221231022311 its reverse (1132201321221), we get a palindrome (2353432343532).

The spelling of 1221231022311 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-one million, twenty-two thousand, three hundred eleven".