6639381718 has 8 divisors (see below), whose sum is σ = 10190679048. Its totient is φ = 3242488704.

The previous prime is 6639381701. The next prime is 6639381743. The reversal of 6639381718 is 8171839366.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38600971 + ... + 38601142.

It is an arithmetic number, because the mean of its divisors is an integer number (1273834881).

Almost surely, 2^6639381718 is an apocalyptic number.

6639381718 is a deficient number, since it is larger than the sum of its proper divisors (3551297330).

6639381718 is a wasteful number, since it uses less digits than its factorization.

6639381718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77202158.

The product of its digits is 1306368, while the sum is 52.

The square root of 6639381718 is about 81482.4012778219. The cubic root of 6639381718 is about 1879.5009349435.

The spelling of 6639381718 in words is "six billion, six hundred thirty-nine million, three hundred eighty-one thousand, seven hundred eighteen".