647665747 has 2 divisors, whose sum is σ = 647665748. Its totient is φ = 647665746.

The previous prime is 647665741. The next prime is 647665771. The reversal of 647665747 is 747566746.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647665747 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 647665694 and 647665703.

It is not a weakly prime, because it can be changed into another prime (647665741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323832873 + 323832874.

It is an arithmetic number, because the mean of its divisors is an integer number (323832874).

Almost surely, 2^647665747 is an apocalyptic number.

647665747 is a deficient number, since it is larger than the sum of its proper divisors (1).

647665747 is an equidigital number, since it uses as much as digits as its factorization.

647665747 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5927040, while the sum is 52.

The square root of 647665747 is about 25449.2779268882. The cubic root of 647665747 is about 865.2009276295.

Subtracting 647665747 from its reverse (747566746), we obtain a palindrome (99900999).

The spelling of 647665747 in words is "six hundred forty-seven million, six hundred sixty-five thousand, seven hundred forty-seven".