1211120001001 has 2 divisors, whose sum is σ = 1211120001002. Its totient is φ = 1211120001000.

The previous prime is 1211120000977. The next prime is 1211120001097. The reversal of 1211120001001 is 1001000211121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 608206575376 + 602913425625 = 779876^2 + 776475^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211120001001 - 2¹⁷ = 1211119869929 is a prime.

It is not a weakly prime, because it can be changed into another prime (1211120001701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605560000500 + 605560000501.

It is an arithmetic number, because the mean of its divisors is an integer number (605560000501).

Almost surely, 2^{1211120001001} is an apocalyptic number.

It is an amenable number.

1211120001001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211120001001 is an equidigital number, since it uses as much as digits as its factorization.

1211120001001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 1211120001001 its reverse (1001000211121), we get a palindrome (2212120212122).

The spelling of 1211120001001 in words is "one trillion, two hundred eleven billion, one hundred twenty million, one thousand, one".