861559 has 2 divisors, whose sum is σ = 861560. Its totient is φ = 861558.

The previous prime is 861551. The next prime is 861563. The reversal of 861559 is 955168.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 861559 - 2³ = 861551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (861551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430779 + 430780.

It is an arithmetic number, because the mean of its divisors is an integer number (430780).

2⁸⁶¹⁵⁵⁹ is an apocalyptic number.

861559 is a deficient number, since it is larger than the sum of its proper divisors (1).

861559 is an equidigital number, since it uses as much as digits as its factorization.

861559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10800, while the sum is 34.

The square root of 861559 is about 928.2020254233. The cubic root of 861559 is about 95.1542830066.

The spelling of 861559 in words is "eight hundred sixty-one thousand, five hundred fifty-nine".