1561236563 has 2 divisors, whose sum is σ = 1561236564. Its totient is φ = 1561236562.

The previous prime is 1561236533. The next prime is 1561236569. The reversal of 1561236563 is 3656321651.

It is a strong prime.

It is an emirp because it is prime and its reverse (3656321651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1561236563 - 2⁸ = 1561236307 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1561236569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 780618281 + 780618282.

It is an arithmetic number, because the mean of its divisors is an integer number (780618282).

Almost surely, 2^1561236563 is an apocalyptic number.

1561236563 is a deficient number, since it is larger than the sum of its proper divisors (1).

1561236563 is an equidigital number, since it uses as much as digits as its factorization.

1561236563 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97200, while the sum is 38.

The square root of 1561236563 is about 39512.4861657679. The cubic root of 1561236563 is about 1160.0843584608.

The spelling of 1561236563 in words is "one billion, five hundred sixty-one million, two hundred thirty-six thousand, five hundred sixty-three".