26561021 has 8 divisors (see below), whose sum is σ = 29346624. Its totient is φ = 23911360.

The previous prime is 26561009. The next prime is 26561027. The reversal of 26561021 is 12016562.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-26561021 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (26561027) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33575 + ... + 34356.

It is an arithmetic number, because the mean of its divisors is an integer number (3668328).

Almost surely, 2^26561021 is an apocalyptic number.

It is an amenable number.

26561021 is a deficient number, since it is larger than the sum of its proper divisors (2785603).

26561021 is a wasteful number, since it uses less digits than its factorization.

26561021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67971.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 26561021 is about 5153.7385459490. The cubic root of 26561021 is about 298.3652601170.

Adding to 26561021 its reverse (12016562), we get a palindrome (38577583).

The spelling of 26561021 in words is "twenty-six million, five hundred sixty-one thousand, twenty-one".