1563561 has 6 divisors (see below), whose sum is σ = 2258490. Its totient is φ = 1042368.

The previous prime is 1563539. The next prime is 1563571. The reversal of 1563561 is 1653651.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1010025 + 553536 = 1005^2 + 744^2 .

It is not a de Polignac number, because 1563561 - 2⁷ = 1563433 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1563511) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 86856 + ... + 86873.

It is an arithmetic number, because the mean of its divisors is an integer number (376415).

2^1563561 is an apocalyptic number.

It is an amenable number.

1563561 is a deficient number, since it is larger than the sum of its proper divisors (694929).

1563561 is a wasteful number, since it uses less digits than its factorization.

1563561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173735 (or 173732 counting only the distinct ones).

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

The square root of 1563561 is about 1250.4243279783. The cubic root of 1563561 is about 116.0659801015.

The spelling of 1563561 in words is "one million, five hundred sixty-three thousand, five hundred sixty-one".