21265241 has 2 divisors, whose sum is σ = 21265242. Its totient is φ = 21265240.

The previous prime is 21265219. The next prime is 21265253. The reversal of 21265241 is 14256212.

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., 13542400 + 7722841 = 3680^2 + 2779^2 .

It is a cyclic number.

It is not a de Polignac number, because 21265241 - 2¹⁸ = 21003097 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21265441) 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, 10632620 + 10632621.

It is an arithmetic number, because the mean of its divisors is an integer number (10632621).

Almost surely, 2^21265241 is an apocalyptic number.

It is an amenable number.

21265241 is a deficient number, since it is larger than the sum of its proper divisors (1).

21265241 is an equidigital number, since it uses as much as digits as its factorization.

21265241 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 23.

The square root of 21265241 is about 4611.4250508926. The cubic root of 21265241 is about 277.0491165667.

The spelling of 21265241 in words is "twenty-one million, two hundred sixty-five thousand, two hundred forty-one".