6638849859 has 16 divisors (see below), whose sum is σ = 8970121472. Its totient is φ = 4367050848.

The previous prime is 6638849849. The next prime is 6638849863. The reversal of 6638849859 is 9589488366.

It is not a de Polignac number, because 6638849859 - 2⁵ = 6638849827 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6638849859.

It is not an unprimeable number, because it can be changed into a prime (6638849849) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46812 + ... + 124374.

It is an arithmetic number, because the mean of its divisors is an integer number (560632592).

Almost surely, 2^6638849859 is an apocalyptic number.

6638849859 is a deficient number, since it is larger than the sum of its proper divisors (2331271613).

6638849859 is a wasteful number, since it uses less digits than its factorization.

6638849859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77946.

The product of its digits is 89579520, while the sum is 66.

The square root of 6638849859 is about 81479.1375690735. The cubic root of 6638849859 is about 1879.4507467270.

The spelling of 6638849859 in words is "six billion, six hundred thirty-eight million, eight hundred forty-nine thousand, eight hundred fifty-nine".