26718561 has 9 divisors (see below), whose sum is σ = 38615889. Its totient is φ = 17802036.

The previous prime is 26718547. The next prime is 26718569. The reversal of 26718561 is 16581762.

The square root of 26718561 is 5169.

It is a perfect power (a square), and thus also a powerful number.

26718561 is a `hidden beast` number, since 26 + 71 + 8 + 561 = 666.

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 26718561 - 2⁵ = 26718529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (26718569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 14646 + ... + 16368.

Almost surely, 2^26718561 is an apocalyptic number.

26718561 is the 5169-th square number.

26718561 is the 2585-th centered octagonal number.

It is an amenable number.

26718561 is a deficient number, since it is larger than the sum of its proper divisors (11897328).

26718561 is an frugal number, since it uses more digits than its factorization.

26718561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3452 (or 1726 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The cubic root of 26718561 is about 298.9539904522.

Multiplying 26718561 by its sum of digits (36), we get a square (961868196 = 31014²).

The spelling of 26718561 in words is "twenty-six million, seven hundred eighteen thousand, five hundred sixty-one".