647662009 has 2 divisors, whose sum is σ = 647662010. Its totient is φ = 647662008.

The previous prime is 647661979. The next prime is 647662019. The reversal of 647662009 is 900266746.

647662009 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 550934784 + 96727225 = 23472^2 + 9835^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-647662009 is a prime.

It is not a weakly prime, because it can be changed into another prime (647662019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 323831004 + 323831005.

It is an arithmetic number, because the mean of its divisors is an integer number (323831005).

Almost surely, 2^647662009 is an apocalyptic number.

It is an amenable number.

647662009 is a deficient number, since it is larger than the sum of its proper divisors (1).

647662009 is an equidigital number, since it uses as much as digits as its factorization.

647662009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108864, while the sum is 40.

The square root of 647662009 is about 25449.2044865846. The cubic root of 647662009 is about 865.1992631252.

The spelling of 647662009 in words is "six hundred forty-seven million, six hundred sixty-two thousand, nine".