861089 has 2 divisors, whose sum is σ = 861090. Its totient is φ = 861088.

The previous prime is 861083. The next prime is 861109. The reversal of 861089 is 980168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 667489 + 193600 = 817^2 + 440^2 .

It is a cyclic number.

It is not a de Polignac number, because 861089 - 2¹² = 856993 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430544 + 430545.

It is an arithmetic number, because the mean of its divisors is an integer number (430545).

2⁸⁶¹⁰⁸⁹ is an apocalyptic number.

It is an amenable number.

861089 is a deficient number, since it is larger than the sum of its proper divisors (1).

861089 is an equidigital number, since it uses as much as digits as its factorization.

861089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 861089 is about 927.9488132435. The cubic root of 861089 is about 95.1369769185.

The spelling of 861089 in words is "eight hundred sixty-one thousand, eighty-nine".