2661191 has 4 divisors (see below), whose sum is σ = 2865912. Its totient is φ = 2456472.

The previous prime is 2661181. The next prime is 2661199. The reversal of 2661191 is 1911662.

2661191 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661191 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 2661191.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661199) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102341 + ... + 102366.

It is an arithmetic number, because the mean of its divisors is an integer number (716478).

2^2661191 is an apocalyptic number.

2661191 is a deficient number, since it is larger than the sum of its proper divisors (204721).

2661191 is a wasteful number, since it uses less digits than its factorization.

2661191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204720.

The product of its digits is 648, while the sum is 26.

The square root of 2661191 is about 1631.3157266452. The cubic root of 2661191 is about 138.5772744498.

The spelling of 2661191 in words is "two million, six hundred sixty-one thousand, one hundred ninety-one".