1991141811 has 32 divisors (see below), whose sum is σ = 3051264000. Its totient is φ = 1281964320.

The previous prime is 1991141807. The next prime is 1991141819. The reversal of 1991141811 is 1181411991.

It is not a de Polignac number, because 1991141811 - 2² = 1991141807 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1991141819) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 455665 + ... + 460013.

It is an arithmetic number, because the mean of its divisors is an integer number (95352000).

Almost surely, 2^1991141811 is an apocalyptic number.

1991141811 is a deficient number, since it is larger than the sum of its proper divisors (1060122189).

1991141811 is a wasteful number, since it uses less digits than its factorization.

1991141811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4936 (or 4930 counting only the distinct ones).

The product of its digits is 2592, while the sum is 36.

The square root of 1991141811 is about 44622.2120809805. The cubic root of 1991141811 is about 1258.0581937959.

The spelling of 1991141811 in words is "one billion, nine hundred ninety-one million, one hundred forty-one thousand, eight hundred eleven".