11491861 has 4 divisors (see below), whose sum is σ = 11507724. Its totient is φ = 11476000.

The previous prime is 11491853. The next prime is 11491873. The reversal of 11491861 is 16819411.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16819411 = 7 ⋅2402773.

It can be written as a sum of positive squares in 2 ways, for example, as 476100 + 11015761 = 690^2 + 3319^2 .

It is a cyclic number.

It is not a de Polignac number, because 11491861 - 2³ = 11491853 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11491841) 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 3 ways as a sum of consecutive naturals, for example, 6790 + ... + 8311.

It is an arithmetic number, because the mean of its divisors is an integer number (2876931).

Almost surely, 2^11491861 is an apocalyptic number.

It is an amenable number.

11491861 is a deficient number, since it is larger than the sum of its proper divisors (15863).

11491861 is an equidigital number, since it uses as much as digits as its factorization.

11491861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15862.

The product of its digits is 1728, while the sum is 31.

The square root of 11491861 is about 3389.9647490793. The cubic root of 11491861 is about 225.6646094163.

The spelling of 11491861 in words is "eleven million, four hundred ninety-one thousand, eight hundred sixty-one".