861589 has 2 divisors, whose sum is σ = 861590. Its totient is φ = 861588.

The previous prime is 861571. The next prime is 861599. The reversal of 861589 is 985168.

861589 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 828100 + 33489 = 910^2 + 183^2 .

It is a cyclic number.

It is not a de Polignac number, because 861589 - 2¹⁹ = 337301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430794 + 430795.

It is an arithmetic number, because the mean of its divisors is an integer number (430795).

2⁸⁶¹⁵⁸⁹ is an apocalyptic number.

It is an amenable number.

861589 is a deficient number, since it is larger than the sum of its proper divisors (1).

861589 is an equidigital number, since it uses as much as digits as its factorization.

861589 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 37.

The square root of 861589 is about 928.2181855577. The cubic root of 861589 is about 95.1553874368.

The spelling of 861589 in words is "eight hundred sixty-one thousand, five hundred eighty-nine".