812861 has 12 divisors (see below), whose sum is σ = 966492. Its totient is φ = 681408.

The previous prime is 812857. The next prime is 812869. The reversal of 812861 is 168218.

It can be written as a sum of positive squares in 2 ways, for example, as 219961 + 592900 = 469^2 + 770^2 .

It is not a de Polignac number, because 812861 - 2² = 812857 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 812861.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (812869) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2441 + ... + 2753.

It is an arithmetic number, because the mean of its divisors is an integer number (80541).

2⁸¹²⁸⁶¹ is an apocalyptic number.

It is an amenable number.

812861 is a deficient number, since it is larger than the sum of its proper divisors (153631).

812861 is a wasteful number, since it uses less digits than its factorization.

812861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 380 (or 373 counting only the distinct ones).

The product of its digits is 768, while the sum is 26.

The square root of 812861 is about 901.5880433990. The cubic root of 812861 is about 93.3265967360.

The spelling of 812861 in words is "eight hundred twelve thousand, eight hundred sixty-one".