1221331210309 has 12 divisors (see below), whose sum is σ = 1469722992300. Its totient is φ = 1010756862528.

The previous prime is 1221331210303. The next prime is 1221331210327. The reversal of 1221331210309 is 9030121331221.

It can be written as a sum of positive squares in 2 ways, for example, as 294534144100 + 926797066209 = 542710^2 + 962703^2 .

It is not a de Polignac number, because 1221331210309 - 2¹⁹ = 1221330686021 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 (1221331210303) 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, 429742144 + ... + 429744985.

It is an arithmetic number, because the mean of its divisors is an integer number (122476916025).

Almost surely, 2^{1221331210309} is an apocalyptic number.

It is an amenable number.

1221331210309 is a deficient number, since it is larger than the sum of its proper divisors (248391781991).

1221331210309 is an equidigital number, since it uses as much as digits as its factorization.

1221331210309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 859487172 (or 859487165 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The spelling of 1221331210309 in words is "one trillion, two hundred twenty-one billion, three hundred thirty-one million, two hundred ten thousand, three hundred nine".