647666746 has 4 divisors (see below), whose sum is σ = 971500122. Its totient is φ = 323833372.

The previous prime is 647666743. The next prime is 647666809.

It is a happy number.

647666746 is nontrivially palindromic in base 10.

647666746 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 599711121 + 47955625 = 24489^2 + 6925^2 .

It is a junction number, because it is equal to n+sod(n) for n = 647666693 and 647666702.

It is not an unprimeable number, because it can be changed into a prime (647666741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161916685 + ... + 161916688.

Almost surely, 2^647666746 is an apocalyptic number.

647666746 is a deficient number, since it is larger than the sum of its proper divisors (323833376).

647666746 is a wasteful number, since it uses less digits than its factorization.

647666746 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323833375.

The product of its digits is 6096384, while the sum is 52.

The square root of 647666746 is about 25449.2975541566. The cubic root of 647666746 is about 865.2013724759.

The spelling of 647666746 in words is "six hundred forty-seven million, six hundred sixty-six thousand, seven hundred forty-six".