1221010811209 has 8 divisors (see below), whose sum is σ = 1395490429440. Its totient is φ = 1046543568576.

The previous prime is 1221010811203. The next prime is 1221010811221. The reversal of 1221010811209 is 9021180101221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221010811209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221010811203) 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 7 ways as a sum of consecutive naturals, for example, 2881504 + ... + 3277969.

It is an arithmetic number, because the mean of its divisors is an integer number (174436303680).

Almost surely, 2^{1221010811209} is an apocalyptic number.

It is an amenable number.

1221010811209 is a deficient number, since it is larger than the sum of its proper divisors (174479618231).

1221010811209 is an equidigital number, since it uses as much as digits as its factorization.

1221010811209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6187799.

The product of its (nonzero) digits is 576, while the sum is 28.

The spelling of 1221010811209 in words is "one trillion, two hundred twenty-one billion, ten million, eight hundred eleven thousand, two hundred nine".