1191135988 has 24 divisors (see below), whose sum is σ = 2410978752. Its totient is φ = 504335424.

The previous prime is 1191135961. The next prime is 1191136007. The reversal of 1191135988 is 8895311911.

It is a super-2 number, since 2×1191135988² = 2837609883817472288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 253945 + ... + 258592.

It is an arithmetic number, because the mean of its divisors is an integer number (100457448).

Almost surely, 2^1191135988 is an apocalyptic number.

It is an amenable number.

1191135988 is an abundant number, since it is smaller than the sum of its proper divisors (1219842764).

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

1191135988 is a wasteful number, since it uses less digits than its factorization.

1191135988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512631 (or 512629 counting only the distinct ones).

The product of its digits is 77760, while the sum is 46.

The square root of 1191135988 is about 34512.8380171785. The cubic root of 1191135988 is about 1060.0355951023.

The spelling of 1191135988 in words is "one billion, one hundred ninety-one million, one hundred thirty-five thousand, nine hundred eighty-eight".