6611999891 has 8 divisors (see below), whose sum is σ = 7557481824. Its totient is φ = 5666745600.

The previous prime is 6611999851. The next prime is 6611999899. The reversal of 6611999891 is 1989991166.

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 6611999891 - 2¹⁰ = 6611998867 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6611999891.

It is not an unprimeable number, because it can be changed into a prime (6611999899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10691 + ... + 115491.

It is an arithmetic number, because the mean of its divisors is an integer number (944685228).

Almost surely, 2^6611999891 is an apocalyptic number.

6611999891 is a deficient number, since it is larger than the sum of its proper divisors (945481933).

6611999891 is a wasteful number, since it uses less digits than its factorization.

6611999891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113821.

The product of its digits is 1889568, while the sum is 59.

The square root of 6611999891 is about 81314.2047307849. The cubic root of 6611999891 is about 1876.9135915789.

The spelling of 6611999891 in words is "six billion, six hundred eleven million, nine hundred ninety-nine thousand, eight hundred ninety-one".