861995 has 4 divisors (see below), whose sum is σ = 1034400. Its totient is φ = 689592.

The previous prime is 861979. The next prime is 861997. The reversal of 861995 is 599168.

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 861995 - 2⁴ = 861979 is a prime.

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 861995.

It is not an unprimeable number, because it can be changed into a prime (861997) 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, 86195 + ... + 86204.

It is an arithmetic number, because the mean of its divisors is an integer number (258600).

2⁸⁶¹⁹⁹⁵ is an apocalyptic number.

861995 is a deficient number, since it is larger than the sum of its proper divisors (172405).

861995 is a wasteful number, since it uses less digits than its factorization.

861995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172404.

The product of its digits is 19440, while the sum is 38.

The square root of 861995 is about 928.4368583808. The cubic root of 861995 is about 95.1703315383.

The spelling of 861995 in words is "eight hundred sixty-one thousand, nine hundred ninety-five".