861911 has 4 divisors (see below), whose sum is σ = 873792. Its totient is φ = 850032.

The previous prime is 861907. The next prime is 861929. The reversal of 861911 is 119168.

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

It is a cyclic number.

It is not a de Polignac number, because 861911 - 2² = 861907 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 (861901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5831 + ... + 5976.

It is an arithmetic number, because the mean of its divisors is an integer number (218448).

2⁸⁶¹⁹¹¹ is an apocalyptic number.

861911 is a deficient number, since it is larger than the sum of its proper divisors (11881).

861911 is a wasteful number, since it uses less digits than its factorization.

861911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11880.

The product of its digits is 432, while the sum is 26.

The square root of 861911 is about 928.3916199536. The cubic root of 861911 is about 95.1672400403.

The spelling of 861911 in words is "eight hundred sixty-one thousand, nine hundred eleven".