861563 has 2 divisors, whose sum is σ = 861564. Its totient is φ = 861562.

The previous prime is 861559. The next prime is 861571. The reversal of 861563 is 365168.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 861563 - 2² = 861559 is a prime.

It is a Chen prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 861563.

It is not a weakly prime, because it can be changed into another prime (861163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430781 + 430782.

It is an arithmetic number, because the mean of its divisors is an integer number (430782).

2⁸⁶¹⁵⁶³ is an apocalyptic number.

861563 is a deficient number, since it is larger than the sum of its proper divisors (1).

861563 is an equidigital number, since it uses as much as digits as its factorization.

861563 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4320, while the sum is 29.

The square root of 861563 is about 928.2041801242. The cubic root of 861563 is about 95.1544302654.

The spelling of 861563 in words is "eight hundred sixty-one thousand, five hundred sixty-three".