1211221000305 has 24 divisors (see below), whose sum is σ = 2099516747328. Its totient is φ = 645963914016.

The previous prime is 1211221000303. The next prime is 1211221000333. The reversal of 1211221000305 is 5030001221121.

It is not a de Polignac number, because 1211221000305 - 2¹ = 1211221000303 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1211221000303) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1052044 + ... + 1878626.

It is an arithmetic number, because the mean of its divisors is an integer number (87479864472).

Almost surely, 2^{1211221000305} is an apocalyptic number.

1211221000305 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1211221000305 is a deficient number, since it is larger than the sum of its proper divisors (888295747023).

1211221000305 is a wasteful number, since it uses less digits than its factorization.

1211221000305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859157 (or 859154 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

Adding to 1211221000305 its reverse (5030001221121), we get a palindrome (6241222221426).

The spelling of 1211221000305 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, three hundred five", and thus it is an aban number.