1221021021199 has 12 divisors (see below), whose sum is σ = 1424327878800. Its totient is φ = 1043674140768.

The previous prime is 1221021021193. The next prime is 1221021021221. The reversal of 1221021021199 is 9911201201221.

It is not a de Polignac number, because 1221021021199 - 2¹⁷ = 1221020890127 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221021021199.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221021021193) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34688254 + ... + 34723435.

It is an arithmetic number, because the mean of its divisors is an integer number (118693989900).

Almost surely, 2^{1221021021199} is an apocalyptic number.

1221021021199 is a deficient number, since it is larger than the sum of its proper divisors (203306857601).

1221021021199 is an equidigital number, since it uses as much as digits as its factorization.

1221021021199 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69412062 (or 69412055 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 31.

The spelling of 1221021021199 in words is "one trillion, two hundred twenty-one billion, twenty-one million, twenty-one thousand, one hundred ninety-nine".