1221321001311 has 12 divisors (see below), whose sum is σ = 1764400619280. Its totient is φ = 814089254400.

The previous prime is 1221321001309. The next prime is 1221321001337. The reversal of 1221321001311 is 1131001231221.

1221321001311 is a `hidden beast` number, since 1 + 221 + 32 + 100 + 1 + 311 = 666.

It is not a de Polignac number, because 1221321001311 - 2¹ = 1221321001309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221321011311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10333515 + ... + 10451036.

It is an arithmetic number, because the mean of its divisors is an integer number (147033384940).

Almost surely, 2^{1221321001311} is an apocalyptic number.

1221321001311 is a deficient number, since it is larger than the sum of its proper divisors (543079617969).

1221321001311 is a wasteful number, since it uses less digits than its factorization.

1221321001311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20791086 (or 20791083 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 1221321001311 its reverse (1131001231221), we get a palindrome (2352322232532).

The spelling of 1221321001311 in words is "one trillion, two hundred twenty-one billion, three hundred twenty-one million, one thousand, three hundred eleven".