1221231020311 has 2 divisors, whose sum is σ = 1221231020312. Its totient is φ = 1221231020310.

The previous prime is 1221231020281. The next prime is 1221231020353. The reversal of 1221231020311 is 1130201321221.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1221231020311 - 2¹⁷ = 1221230889239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221231020371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610615510155 + 610615510156.

It is an arithmetic number, because the mean of its divisors is an integer number (610615510156).

Almost surely, 2^{1221231020311} is an apocalyptic number.

1221231020311 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221231020311 is an equidigital number, since it uses as much as digits as its factorization.

1221231020311 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 1221231020311 its reverse (1130201321221), we get a palindrome (2351432341532).

The spelling of 1221231020311 in words is "one trillion, two hundred twenty-one billion, two hundred thirty-one million, twenty thousand, three hundred eleven".