1211100999971 has 2 divisors, whose sum is σ = 1211100999972. Its totient is φ = 1211100999970.

The previous prime is 1211100999917. The next prime is 1211101000009. The reversal of 1211100999971 is 1799990011121.

Together with previous prime (1211100999917) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211100999971 is a prime.

It is a super-2 number, since 2×1211100999971² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1211100992971) 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, 605550499985 + 605550499986.

It is an arithmetic number, because the mean of its divisors is an integer number (605550499986).

Almost surely, 2^{1211100999971} is an apocalyptic number.

1211100999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

1211100999971 is an equidigital number, since it uses as much as digits as its factorization.

1211100999971 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 91854, while the sum is 50.

The spelling of 1211100999971 in words is "one trillion, two hundred eleven billion, one hundred million, nine hundred ninety-nine thousand, nine hundred seventy-one".