26811561 has 16 divisors (see below), whose sum is σ = 41263488. Its totient is φ = 15168000.

The previous prime is 26811557. The next prime is 26811593. The reversal of 26811561 is 16511862.

It is not a de Polignac number, because 26811561 - 2² = 26811557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (26811511) 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, 4200 + ... + 8441.

It is an arithmetic number, because the mean of its divisors is an integer number (2578968).

Almost surely, 2^26811561 is an apocalyptic number.

26811561 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

26811561 is a deficient number, since it is larger than the sum of its proper divisors (14451927).

26811561 is a wasteful number, since it uses less digits than its factorization.

26811561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12752.

The product of its digits is 2880, while the sum is 30.

The square root of 26811561 is about 5177.9881228137. The cubic root of 26811561 is about 299.3004478015.

It can be divided in two parts, 26811 and 561, that added together give a palindrome (27372).

The spelling of 26811561 in words is "twenty-six million, eight hundred eleven thousand, five hundred sixty-one".