647139239 has 2 divisors, whose sum is σ = 647139240. Its totient is φ = 647139238.

The previous prime is 647139217. The next prime is 647139253. The reversal of 647139239 is 932931746.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 647139239 - 2²⁰ = 646090663 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 647139239.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (647139299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323569619 + 323569620.

It is an arithmetic number, because the mean of its divisors is an integer number (323569620).

Almost surely, 2^647139239 is an apocalyptic number.

647139239 is a deficient number, since it is larger than the sum of its proper divisors (1).

647139239 is an equidigital number, since it uses as much as digits as its factorization.

647139239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 244944, while the sum is 44.

The square root of 647139239 is about 25438.9315616832. The cubic root of 647139239 is about 864.9664143241.

The spelling of 647139239 in words is "six hundred forty-seven million, one hundred thirty-nine thousand, two hundred thirty-nine".