861597 has 20 divisors (see below), whose sum is σ = 1405536. Its totient is φ = 521640.

The previous prime is 861589. The next prime is 861599. The reversal of 861597 is 795168.

861597 is a `hidden beast` number, since 8 + 61 + 597 = 666.

It is not a de Polignac number, because 861597 - 2³ = 861589 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861599) 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 19 ways as a sum of consecutive naturals, for example, 408 + ... + 1374.

2⁸⁶¹⁵⁹⁷ is an apocalyptic number.

It is an amenable number.

861597 is a deficient number, since it is larger than the sum of its proper divisors (543939).

861597 is a wasteful number, since it uses less digits than its factorization.

861597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990 (or 981 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 861597 is about 928.2224948793. Note that the first 3 decimals coincide. The cubic root of 861597 is about 95.1556819472.

The spelling of 861597 in words is "eight hundred sixty-one thousand, five hundred ninety-seven".