1211328811791 has 288 divisors, whose sum is σ = 2260318894080. Its totient is φ = 620786073600.

The previous prime is 1211328811757. The next prime is 1211328811807. The reversal of 1211328811791 is 1971188231121.

1211328811791 is a `hidden beast` number, since 121 + 1 + 328 + 8 + 117 + 91 = 666.

It is not a de Polignac number, because 1211328811791 - 2⁹ = 1211328811279 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211328811751) by changing a digit.

It is a polite number, since it can be written in 287 ways as a sum of consecutive naturals, for example, 3659603496 + ... + 3659603826.

Almost surely, 2^{1211328811791} is an apocalyptic number.

1211328811791 is a deficient number, since it is larger than the sum of its proper divisors (1048990082289).

1211328811791 is a wasteful number, since it uses less digits than its factorization.

1211328811791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 667 (or 657 counting only the distinct ones).

The product of its digits is 48384, while the sum is 45.

The spelling of 1211328811791 in words is "one trillion, two hundred eleven billion, three hundred twenty-eight million, eight hundred eleven thousand, seven hundred ninety-one".