11691881 has 8 divisors (see below), whose sum is σ = 11880000. Its totient is φ = 11505520.

The previous prime is 11691877. The next prime is 11691907. The reversal of 11691881 is 18819611.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11691881 - 2² = 11691877 is a prime.

It is a super-2 number, since 2×11691881² = 273400162636322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11691851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19220 + ... + 19818.

It is an arithmetic number, because the mean of its divisors is an integer number (1485000).

Almost surely, 2^11691881 is an apocalyptic number.

It is an amenable number.

11691881 is a deficient number, since it is larger than the sum of its proper divisors (188119).

11691881 is a wasteful number, since it uses less digits than its factorization.

11691881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 879.

The product of its digits is 3456, while the sum is 35.

The square root of 11691881 is about 3419.3392636590. The cubic root of 11691881 is about 226.9663440564.

The spelling of 11691881 in words is "eleven million, six hundred ninety-one thousand, eight hundred eighty-one".