6441558857 has 4 divisors (see below), whose sum is σ = 6464482836. Its totient is φ = 6418634880.

The previous prime is 6441558811. The next prime is 6441558887. The reversal of 6441558857 is 7588551446.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3338066176 + 3103492681 = 57776^2 + 55709^2 .

It is a cyclic number.

It is not a de Polignac number, because 6441558857 - 2⁸ = 6441558601 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6441558799 and 6441558808.

It is not an unprimeable number, because it can be changed into a prime (6441558887) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11461568 + ... + 11462129.

It is an arithmetic number, because the mean of its divisors is an integer number (1616120709).

Almost surely, 2^6441558857 is an apocalyptic number.

It is an amenable number.

6441558857 is a deficient number, since it is larger than the sum of its proper divisors (22923979).

6441558857 is a wasteful number, since it uses less digits than its factorization.

6441558857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22923978.

The product of its digits is 5376000, while the sum is 53.

The square root of 6441558857 is about 80259.3225550777. The cubic root of 6441558857 is about 1860.6455978539.

The spelling of 6441558857 in words is "six billion, four hundred forty-one million, five hundred fifty-eight thousand, eight hundred fifty-seven".