647644679 has 8 divisors (see below), whose sum is σ = 706777488. Its totient is φ = 588554560.

The previous prime is 647644663. The next prime is 647644687. The reversal of 647644679 is 976446746.

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

It is not a de Polignac number, because 647644679 - 2⁴ = 647644663 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 647644679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (647644639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26789 + ... + 44865.

It is an arithmetic number, because the mean of its divisors is an integer number (88347186).

Almost surely, 2^647644679 is an apocalyptic number.

647644679 is a deficient number, since it is larger than the sum of its proper divisors (59132809).

647644679 is a wasteful number, since it uses less digits than its factorization.

647644679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21345.

The product of its digits is 6096384, while the sum is 53.

The square root of 647644679 is about 25448.8640021515. The cubic root of 647644679 is about 865.1915461181.

The spelling of 647644679 in words is "six hundred forty-seven million, six hundred forty-four thousand, six hundred seventy-nine".