1211002111001 has 2 divisors, whose sum is σ = 1211002111002. Its totient is φ = 1211002111000.

The previous prime is 1211002110953. The next prime is 1211002111021. The reversal of 1211002111001 is 1001112001121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 832683625225 + 378318485776 = 912515^2 + 615076^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211002111001 - 2⁶ = 1211002110937 is a prime.

It is a super-2 number, since 2×1211002111001² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1211002111021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 605501055500 + 605501055501.

It is an arithmetic number, because the mean of its divisors is an integer number (605501055501).

Almost surely, 2^{1211002111001} is an apocalyptic number.

It is an amenable number.

1211002111001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211002111001 is an equidigital number, since it uses as much as digits as its factorization.

1211002111001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4, while the sum is 11.

Adding to 1211002111001 its reverse (1001112001121), we get a palindrome (2212114112122).

The spelling of 1211002111001 in words is "one trillion, two hundred eleven billion, two million, one hundred eleven thousand, one".