6645924281 has 2 divisors, whose sum is σ = 6645924282. Its totient is φ = 6645924280.

The previous prime is 6645924269. The next prime is 6645924317. The reversal of 6645924281 is 1824295466.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6558408256 + 87516025 = 80984^2 + 9355^2 .

It is a cyclic number.

It is not a de Polignac number, because 6645924281 - 2¹⁴ = 6645907897 is a prime.

It is a super-2 number, since 2×6645924281² = 88336619097570733922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6645954281) 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, 3322962140 + 3322962141.

It is an arithmetic number, because the mean of its divisors is an integer number (3322962141).

Almost surely, 2^6645924281 is an apocalyptic number.

It is an amenable number.

6645924281 is a deficient number, since it is larger than the sum of its proper divisors (1).

6645924281 is an equidigital number, since it uses as much as digits as its factorization.

6645924281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 829440, while the sum is 47.

The square root of 6645924281 is about 81522.5384847651. The cubic root of 6645924281 is about 1880.1180966442.

The spelling of 6645924281 in words is "six billion, six hundred forty-five million, nine hundred twenty-four thousand, two hundred eighty-one".