1211110101001 has 2 divisors, whose sum is σ = 1211110101002. Its totient is φ = 1211110101000.

The previous prime is 1211110100969. The next prime is 1211110101023. The reversal of 1211110101001 is 1001010111121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1076248555776 + 134861545225 = 1037424^2 + 367235^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211110101001 - 2⁵ = 1211110100969 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211110101031) 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 as a sum of consecutive naturals, namely, 605555050500 + 605555050501.

It is an arithmetic number, because the mean of its divisors is an integer number (605555050501).

Almost surely, 2^{1211110101001} is an apocalyptic number.

It is an amenable number.

1211110101001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211110101001 is an equidigital number, since it uses as much as digits as its factorization.

1211110101001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2, while the sum is 10.

Adding to 1211110101001 its reverse (1001010111121), we get a palindrome (2212120212122).

The spelling of 1211110101001 in words is "one trillion, two hundred eleven billion, one hundred ten million, one hundred one thousand, one".