26561563 has 16 divisors (see below), whose sum is σ = 32739840. Its totient is φ = 21038400.

The previous prime is 26561551. The next prime is 26561581. The reversal of 26561563 is 36516562.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26561563 is a prime.

It is not an unprimeable number, because it can be changed into a prime (26561503) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3018 + ... + 7888.

It is an arithmetic number, because the mean of its divisors is an integer number (2046240).

Almost surely, 2^26561563 is an apocalyptic number.

26561563 is a deficient number, since it is larger than the sum of its proper divisors (6178277).

26561563 is a wasteful number, since it uses less digits than its factorization.

26561563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4938.

The product of its digits is 32400, while the sum is 34.

The square root of 26561563 is about 5153.7911288681. The cubic root of 26561563 is about 298.3672895680.

The spelling of 26561563 in words is "twenty-six million, five hundred sixty-one thousand, five hundred sixty-three".