1221011323311 has 16 divisors (see below), whose sum is σ = 1763041714560. Its totient is φ = 747193860960.

The previous prime is 1221011323291. The next prime is 1221011323319. The reversal of 1221011323311 is 1133231101221.

It is not a de Polignac number, because 1221011323311 - 2⁹ = 1221011322799 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221011323319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87445485 + ... + 87459446.

It is an arithmetic number, because the mean of its divisors is an integer number (110190107160).

Almost surely, 2^{1221011323311} is an apocalyptic number.

1221011323311 is a deficient number, since it is larger than the sum of its proper divisors (542030391249).

1221011323311 is a wasteful number, since it uses less digits than its factorization.

1221011323311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174905126.

The product of its (nonzero) digits is 216, while the sum is 21.

Adding to 1221011323311 its reverse (1133231101221), we get a palindrome (2354242424532).

The spelling of 1221011323311 in words is "one trillion, two hundred twenty-one billion, eleven million, three hundred twenty-three thousand, three hundred eleven".