1561559 has 2 divisors, whose sum is σ = 1561560. Its totient is φ = 1561558.

The previous prime is 1561541. The next prime is 1561577. The reversal of 1561559 is 9551651.

It is a balanced prime because it is at equal distance from previous prime (1561541) and next prime (1561577).

It is a cyclic number.

It is not a de Polignac number, because 1561559 - 2⁸ = 1561303 is a prime.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1561519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780779 + 780780.

It is an arithmetic number, because the mean of its divisors is an integer number (780780).

2^1561559 is an apocalyptic number.

1561559 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561559 is an equidigital number, since it uses as much as digits as its factorization.

1561559 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6750, while the sum is 32.

The square root of 1561559 is about 1249.6235433121. The cubic root of 1561559 is about 116.0164215753.

The spelling of 1561559 in words is "one million, five hundred sixty-one thousand, five hundred fifty-nine".