858661 has 6 divisors (see below), whose sum is σ = 890162. Its totient is φ = 828240.

The previous prime is 858631. The next prime is 858673. The reversal of 858661 is 166858.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 168100 + 690561 = 410^2 + 831^2 .

It is not a de Polignac number, because 858661 - 2⁹ = 858149 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 (858631) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 331 + ... + 1351.

2⁸⁵⁸⁶⁶¹ is an apocalyptic number.

It is an amenable number.

858661 is a deficient number, since it is larger than the sum of its proper divisors (31501).

858661 is a wasteful number, since it uses less digits than its factorization.

858661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1079 (or 1050 counting only the distinct ones).

The product of its digits is 11520, while the sum is 34.

The square root of 858661 is about 926.6396279029. The cubic root of 858661 is about 95.0474739637.

The spelling of 858661 in words is "eight hundred fifty-eight thousand, six hundred sixty-one".