26540021 has 2 divisors, whose sum is σ = 26540022. Its totient is φ = 26540020.

The previous prime is 26540011. The next prime is 26540027. The reversal of 26540021 is 12004562.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14212900 + 12327121 = 3770^2 + 3511^2 .

It is a cyclic number.

It is not a de Polignac number, because 26540021 - 2⁶ = 26539957 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 26539975 and 26540002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26540027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13270010 + 13270011.

It is an arithmetic number, because the mean of its divisors is an integer number (13270011).

Almost surely, 2^26540021 is an apocalyptic number.

It is an amenable number.

26540021 is a deficient number, since it is larger than the sum of its proper divisors (1).

26540021 is an equidigital number, since it uses as much as digits as its factorization.

26540021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 26540021 is about 5151.7007871188. The cubic root of 26540021 is about 298.2866069851.

Adding to 26540021 its reverse (12004562), we get a palindrome (38544583).

The spelling of 26540021 in words is "twenty-six million, five hundred forty thousand, twenty-one".