646646648 has 8 divisors (see below), whose sum is σ = 1212462480. Its totient is φ = 323323320.

The previous prime is 646646641. The next prime is 646646653. The reversal of 646646648 is 846646646.

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 646646596 and 646646605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646646641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40415408 + ... + 40415423.

It is an arithmetic number, because the mean of its divisors is an integer number (151557810).

Almost surely, 2^646646648 is an apocalyptic number.

It is an amenable number.

646646648 is a deficient number, since it is larger than the sum of its proper divisors (565815832).

646646648 is a wasteful number, since it uses less digits than its factorization.

646646648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80830837 (or 80830833 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 50.

The square root of 646646648 is about 25429.2478850634. The cubic root of 646646648 is about 864.7468928786.

The spelling of 646646648 in words is "six hundred forty-six million, six hundred forty-six thousand, six hundred forty-eight".