1211021100109 has 2 divisors, whose sum is σ = 1211021100110. Its totient is φ = 1211021100108.

The previous prime is 1211021100067. The next prime is 1211021100193. The reversal of 1211021100109 is 9010011201121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 851024700100 + 359996400009 = 922510^2 + 599997^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211021100109 - 2⁹ = 1211021099597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1211021110109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605510550054 + 605510550055.

It is an arithmetic number, because the mean of its divisors is an integer number (605510550055).

Almost surely, 2^{1211021100109} is an apocalyptic number.

It is an amenable number.

1211021100109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211021100109 is an equidigital number, since it uses as much as digits as its factorization.

1211021100109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36, while the sum is 19.

The spelling of 1211021100109 in words is "one trillion, two hundred eleven billion, twenty-one million, one hundred thousand, one hundred nine".