1211002011001 has 2 divisors, whose sum is σ = 1211002011002. Its totient is φ = 1211002011000.

The previous prime is 1211002010971. The next prime is 1211002011053. The reversal of 1211002011001 is 1001102001121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 954677509776 + 256324501225 = 977076^2 + 506285^2 .

It is an emirp because it is prime and its reverse (1001102001121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211002011001 is a prime.

It is a super-2 number, since 2×1211002011001² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1211002011101) 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, 605501005500 + 605501005501.

It is an arithmetic number, because the mean of its divisors is an integer number (605501005501).

Almost surely, 2^{1211002011001} is an apocalyptic number.

It is an amenable number.

1211002011001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211002011001 is an equidigital number, since it uses as much as digits as its factorization.

1211002011001 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 1211002011001 its reverse (1001102001121), we get a palindrome (2212104012122).

The spelling of 1211002011001 in words is "one trillion, two hundred eleven billion, two million, eleven thousand, one".