1221135311221 has 16 divisors (see below), whose sum is σ = 1398637903104. Its totient is φ = 1044398323584.

The previous prime is 1221135311177. The next prime is 1221135311281.

1221135311221 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 1221135311221 - 2¹⁹ = 1221134786933 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 (1221135311281) 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, 7621491 + ... + 7780063.

It is an arithmetic number, because the mean of its divisors is an integer number (87414868944).

Almost surely, 2^{1221135311221} is an apocalyptic number.

It is an amenable number.

1221135311221 is a deficient number, since it is larger than the sum of its proper divisors (177502591883).

1221135311221 is a wasteful number, since it uses less digits than its factorization.

1221135311221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160980.

The product of its digits is 720, while the sum is 25.

The spelling of 1221135311221 in words is "one trillion, two hundred twenty-one billion, one hundred thirty-five million, three hundred eleven thousand, two hundred twenty-one".