861945 has 16 divisors (see below), whose sum is σ = 1576320. Its totient is φ = 393984.

The previous prime is 861941. The next prime is 861947. The reversal of 861945 is 549168.

It is not a de Polignac number, because 861945 - 2² = 861941 is a prime.

861945 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (861941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4000 + ... + 4209.

It is an arithmetic number, because the mean of its divisors is an integer number (98520).

2⁸⁶¹⁹⁴⁵ is an apocalyptic number.

It is an amenable number.

861945 is a deficient number, since it is larger than the sum of its proper divisors (714375).

861945 is a wasteful number, since it uses less digits than its factorization.

861945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8224.

The product of its digits is 8640, while the sum is 33.

The square root of 861945 is about 928.4099310111. The cubic root of 861945 is about 95.1684913851.

The spelling of 861945 in words is "eight hundred sixty-one thousand, nine hundred forty-five".