26564561 has 4 divisors (see below), whose sum is σ = 26637312. Its totient is φ = 26491812.

The previous prime is 26564543. The next prime is 26564567. The reversal of 26564561 is 16546562.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26564561 is a prime.

It is a super-2 number, since 2×26564561² = 1411351802245442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (26564567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35825 + ... + 36558.

It is an arithmetic number, because the mean of its divisors is an integer number (6659328).

Almost surely, 2^26564561 is an apocalyptic number.

It is an amenable number.

26564561 is a deficient number, since it is larger than the sum of its proper divisors (72751).

26564561 is an equidigital number, since it uses as much as digits as its factorization.

26564561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72750.

The product of its digits is 43200, while the sum is 35.

The square root of 26564561 is about 5154.0819745130. The cubic root of 26564561 is about 298.3785147042.

The spelling of 26564561 in words is "twenty-six million, five hundred sixty-four thousand, five hundred sixty-one".