1221000023311 has 16 divisors (see below), whose sum is σ = 1300423348224. Its totient is φ = 1142440689024.

The previous prime is 1221000023303. The next prime is 1221000023323. The reversal of 1221000023311 is 1133200001221.

It is not a de Polignac number, because 1221000023311 - 2³ = 1221000023303 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000023371) 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 15 ways as a sum of consecutive naturals, for example, 1693456 + ... + 2304298.

It is an arithmetic number, because the mean of its divisors is an integer number (81276459264).

Almost surely, 2^{1221000023311} is an apocalyptic number.

1221000023311 is a deficient number, since it is larger than the sum of its proper divisors (79423324913).

1221000023311 is a wasteful number, since it uses less digits than its factorization.

1221000023311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 611550.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 1221000023311 its reverse (1133200001221), we get a palindrome (2354200024532).

The spelling of 1221000023311 in words is "one trillion, two hundred twenty-one billion, twenty-three thousand, three hundred eleven".