6440678113 has 4 divisors (see below), whose sum is σ = 6487690500. Its totient is φ = 6393665728.

The previous prime is 6440678099. The next prime is 6440678129. The reversal of 6440678113 is 3118760446.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3118760446 = 2 ⋅1559380223.

It can be written as a sum of positive squares in 2 ways, for example, as 5211684864 + 1228993249 = 72192^2 + 35057^2 .

It is a cyclic number.

It is not a de Polignac number, because 6440678113 - 2²¹ = 6438580961 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6440678143) 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, 23505988 + ... + 23506261.

It is an arithmetic number, because the mean of its divisors is an integer number (1621922625).

Almost surely, 2^6440678113 is an apocalyptic number.

It is an amenable number.

6440678113 is a deficient number, since it is larger than the sum of its proper divisors (47012387).

6440678113 is a wasteful number, since it uses less digits than its factorization.

6440678113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47012386.

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 6440678113 is about 80253.8355033577. The cubic root of 6440678113 is about 1860.5607929603.

The spelling of 6440678113 in words is "six billion, four hundred forty million, six hundred seventy-eight thousand, one hundred thirteen".