6440005541 has 2 divisors, whose sum is σ = 6440005542. Its totient is φ = 6440005540.

The previous prime is 6440005463. The next prime is 6440005547. The reversal of 6440005541 is 1455000446.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5483402500 + 956603041 = 74050^2 + 30929^2 .

It is a cyclic number.

It is not a de Polignac number, because 6440005541 - 2³⁰ = 5366263717 is a prime.

It is a super-2 number, since 2×6440005541² = 82947342736221405362, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6440005547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3220002770 + 3220002771.

It is an arithmetic number, because the mean of its divisors is an integer number (3220002771).

Almost surely, 2^6440005541 is an apocalyptic number.

It is an amenable number.

6440005541 is a deficient number, since it is larger than the sum of its proper divisors (1).

6440005541 is an equidigital number, since it uses as much as digits as its factorization.

6440005541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 6440005541 is about 80249.6451144801. The cubic root of 6440005541 is about 1860.4960272823.

Adding to 6440005541 its reverse (1455000446), we get a palindrome (7895005987).

The spelling of 6440005541 in words is "six billion, four hundred forty million, five thousand, five hundred forty-one".