861345 has 12 divisors (see below), whose sum is σ = 1493076. Its totient is φ = 459360.

The previous prime is 861317. The next prime is 861347. The reversal of 861345 is 543168.

861345 is a `hidden beast` number, since 8 + 613 + 45 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 389376 + 471969 = 624^2 + 687^2 .

It is not a de Polignac number, because 861345 - 2⁸ = 861089 is a prime.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

861345 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (861347) 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, 9526 + ... + 9615.

It is an arithmetic number, because the mean of its divisors is an integer number (124423).

2⁸⁶¹³⁴⁵ is an apocalyptic number.

It is an amenable number.

861345 is a deficient number, since it is larger than the sum of its proper divisors (631731).

861345 is a wasteful number, since it uses less digits than its factorization.

861345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19152 (or 19149 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 861345 is about 928.0867416357. The cubic root of 861345 is about 95.1464039939.

It can be divided in two parts, 86 and 1345, that added together give a triangular number (1431 = T₅₃).

The spelling of 861345 in words is "eight hundred sixty-one thousand, three hundred forty-five".