6445618281 has 16 divisors (see below), whose sum is σ = 9647512000. Its totient is φ = 4252777344.

The previous prime is 6445618259. The next prime is 6445618307. The reversal of 6445618281 is 1828165446.

It is a happy number.

6445618281 is a `hidden beast` number, since 6 + 4 + 4 + 5 + 618 + 28 + 1 = 666.

It is not a de Polignac number, because 6445618281 - 2⁶ = 6445618217 is a prime.

It is a super-2 number, since 2×6445618281² = 83091990048722789922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6445618481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1227931 + ... + 1233168.

It is an arithmetic number, because the mean of its divisors is an integer number (602969500).

Almost surely, 2^6445618281 is an apocalyptic number.

It is an amenable number.

6445618281 is a deficient number, since it is larger than the sum of its proper divisors (3201893719).

6445618281 is a wasteful number, since it uses less digits than its factorization.

6445618281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2461205 (or 2461199 counting only the distinct ones).

The product of its digits is 368640, while the sum is 45.

The square root of 6445618281 is about 80284.6079955554. The cubic root of 6445618281 is about 1861.0363709298.

The spelling of 6445618281 in words is "six billion, four hundred forty-five million, six hundred eighteen thousand, two hundred eighty-one".