26031221 has 2 divisors, whose sum is σ = 26031222. Its totient is φ = 26031220.

The previous prime is 26031217. The next prime is 26031253. The reversal of 26031221 is 12213062.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25654225 + 376996 = 5065^2 + 614^2 .

It is a cyclic number.

It is not a de Polignac number, because 26031221 - 2² = 26031217 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 26031221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (26031721) 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 as a sum of consecutive naturals, namely, 13015610 + 13015611.

It is an arithmetic number, because the mean of its divisors is an integer number (13015611).

Almost surely, 2^26031221 is an apocalyptic number.

It is an amenable number.

26031221 is a deficient number, since it is larger than the sum of its proper divisors (1).

26031221 is an equidigital number, since it uses as much as digits as its factorization.

26031221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 26031221 is about 5102.0800660123. The cubic root of 26031221 is about 296.3681390109.

Adding to 26031221 its reverse (12213062), we get a palindrome (38244283).

The spelling of 26031221 in words is "twenty-six million, thirty-one thousand, two hundred twenty-one".