1561563 has 24 divisors (see below), whose sum is σ = 2421120. Its totient is φ = 967680.

The previous prime is 1561559. The next prime is 1561577. The reversal of 1561563 is 3651651.

It is a happy number.

It is not a de Polignac number, because 1561563 - 2² = 1561559 is a prime.

1561563 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (1561163) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7995 + ... + 8187.

It is an arithmetic number, because the mean of its divisors is an integer number (100880).

2^1561563 is an apocalyptic number.

1561563 is a deficient number, since it is larger than the sum of its proper divisors (859557).

1561563 is a wasteful number, since it uses less digits than its factorization.

1561563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259 (or 256 counting only the distinct ones).

The product of its digits is 2700, while the sum is 27.

The square root of 1561563 is about 1249.6251437931. The cubic root of 1561563 is about 116.0165206355.

The spelling of 1561563 in words is "one million, five hundred sixty-one thousand, five hundred sixty-three".