647611639 has 2 divisors, whose sum is σ = 647611640. Its totient is φ = 647611638.

The previous prime is 647611633. The next prime is 647611709. The reversal of 647611639 is 936116746.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 647611639 - 2³ = 647611631 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 647611595 and 647611604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647611631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323805819 + 323805820.

It is an arithmetic number, because the mean of its divisors is an integer number (323805820).

Almost surely, 2^647611639 is an apocalyptic number.

647611639 is a deficient number, since it is larger than the sum of its proper divisors (1).

647611639 is an equidigital number, since it uses as much as digits as its factorization.

647611639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 43.

The square root of 647611639 is about 25448.2148489830. The cubic root of 647611639 is about 865.1768331046.

The spelling of 647611639 in words is "six hundred forty-seven million, six hundred eleven thousand, six hundred thirty-nine".