1191081509808 has 160 divisors (see below), whose sum is σ = 3268446966720. Its totient is φ = 372471889920.

The previous prime is 1191081509773. The next prime is 1191081509873. The reversal of 1191081509808 is 8089051801911.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 391672768 + ... + 391675808.

It is an arithmetic number, because the mean of its divisors is an integer number (20427793542).

Almost surely, 2^{1191081509808} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1191081509808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1634223483360).

1191081509808 is an abundant number, since it is smaller than the sum of its proper divisors (2077365456912).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1191081509808 is a wasteful number, since it uses less digits than its factorization.

1191081509808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4455 (or 4449 counting only the distinct ones).

The product of its (nonzero) digits is 207360, while the sum is 51.

The spelling of 1191081509808 in words is "one trillion, one hundred ninety-one billion, eighty-one million, five hundred nine thousand, eight hundred eight".