1221000211109 has 4 divisors (see below), whose sum is σ = 1395428812704. Its totient is φ = 1046571609516.

The previous prime is 1221000211087. The next prime is 1221000211117. The reversal of 1221000211109 is 9011120001221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221000211109 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 (1221000231109) 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 3 ways as a sum of consecutive naturals, for example, 87214300787 + ... + 87214300800.

It is an arithmetic number, because the mean of its divisors is an integer number (348857203176).

Almost surely, 2^{1221000211109} is an apocalyptic number.

It is an amenable number.

1221000211109 is a deficient number, since it is larger than the sum of its proper divisors (174428601595).

1221000211109 is an equidigital number, since it uses as much as digits as its factorization.

1221000211109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174428601594.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 1221000211109 in words is "one trillion, two hundred twenty-one billion, two hundred eleven thousand, one hundred nine".