1091191779 has 24 divisors (see below), whose sum is σ = 1628847792. Its totient is φ = 703483200.

The previous prime is 1091191757. The next prime is 1091191789. The reversal of 1091191779 is 9771911901.

It is not a de Polignac number, because 1091191779 - 2⁹ = 1091191267 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1091191789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 25129 + ... + 53045.

It is an arithmetic number, because the mean of its divisors is an integer number (67868658).

Almost surely, 2^1091191779 is an apocalyptic number.

1091191779 is a deficient number, since it is larger than the sum of its proper divisors (537656013).

1091191779 is a wasteful number, since it uses less digits than its factorization.

1091191779 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28067 (or 28064 counting only the distinct ones).

The product of its (nonzero) digits is 35721, while the sum is 45.

The square root of 1091191779 is about 33033.1920800882. The cubic root of 1091191779 is about 1029.5174095804.

The spelling of 1091191779 in words is "one billion, ninety-one million, one hundred ninety-one thousand, seven hundred seventy-nine".