861918 has 8 divisors (see below), whose sum is σ = 1723848. Its totient is φ = 287304.

The previous prime is 861907. The next prime is 861929. The reversal of 861918 is 819168.

It is an interprime number because it is at equal distance from previous prime (861907) and next prime (861929).

It is a sphenic number, since it is the product of 3 distinct primes.

861918 is an admirable number.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 861918.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71821 + ... + 71832.

It is an arithmetic number, because the mean of its divisors is an integer number (215481).

2⁸⁶¹⁹¹⁸ is an apocalyptic number.

861918 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

861918 is a wasteful number, since it uses less digits than its factorization.

861918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143658.

The product of its digits is 3456, while the sum is 33.

The square root of 861918 is about 928.3953899067. The cubic root of 861918 is about 95.1674976728.

The spelling of 861918 in words is "eight hundred sixty-one thousand, nine hundred eighteen".