861673 has 4 divisors (see below), whose sum is σ = 864468. Its totient is φ = 858880.

The previous prime is 861659. The next prime is 861691. The reversal of 861673 is 376168.

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

It can be written as a sum of positive squares in 2 ways, for example, as 200704 + 660969 = 448^2 + 813^2 .

It is a cyclic number.

It is not a de Polignac number, because 861673 - 2¹³ = 853481 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861613) 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, 868 + ... + 1573.

It is an arithmetic number, because the mean of its divisors is an integer number (216117).

2⁸⁶¹⁶⁷³ is an apocalyptic number.

It is an amenable number.

861673 is a deficient number, since it is larger than the sum of its proper divisors (2795).

861673 is a wasteful number, since it uses less digits than its factorization.

861673 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2794.

The product of its digits is 6048, while the sum is 31.

The square root of 861673 is about 928.2634324372. The cubic root of 861673 is about 95.1584797050.

Subtracting from 861673 its product of digits (6048), we obtain a square (855625 = 925²).

The spelling of 861673 in words is "eight hundred sixty-one thousand, six hundred seventy-three".