21540041441 has 2 divisors, whose sum is σ = 21540041442. Its totient is φ = 21540041440.

The previous prime is 21540041423. The next prime is 21540041447. The reversal of 21540041441 is 14414004512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18138702400 + 3401339041 = 134680^2 + 58321^2 .

It is a cyclic number.

It is not a de Polignac number, because 21540041441 - 2¹⁴ = 21540025057 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21540041441.

It is not a weakly prime, because it can be changed into another prime (21540041447) 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, 10770020720 + 10770020721.

It is an arithmetic number, because the mean of its divisors is an integer number (10770020721).

Almost surely, 2^21540041441 is an apocalyptic number.

It is an amenable number.

21540041441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21540041441 is an equidigital number, since it uses as much as digits as its factorization.

21540041441 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2560, while the sum is 26.

Adding to 21540041441 its reverse (14414004512), we get a palindrome (35954045953).

The spelling of 21540041441 in words is "twenty-one billion, five hundred forty million, forty-one thousand, four hundred forty-one".