11891865 has 32 divisors (see below), whose sum is σ = 19768320. Its totient is φ = 6100416.

The previous prime is 11891833. The next prime is 11891917. The reversal of 11891865 is 56819811.

It is not a de Polignac number, because 11891865 - 2⁵ = 11891833 is a prime.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 66346 + ... + 66524.

It is an arithmetic number, because the mean of its divisors is an integer number (617760).

Almost surely, 2^11891865 is an apocalyptic number.

11891865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11891865 is a deficient number, since it is larger than the sum of its proper divisors (7876455).

11891865 is a wasteful number, since it uses less digits than its factorization.

11891865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333.

The product of its digits is 17280, while the sum is 39.

The square root of 11891865 is about 3448.4583512057. The cubic root of 11891865 is about 228.2530853857.

The spelling of 11891865 in words is "eleven million, eight hundred ninety-one thousand, eight hundred sixty-five".