646666040 has 32 divisors (see below), whose sum is σ = 1455723360. Its totient is φ = 258537600.

The previous prime is 646666039. The next prime is 646666049. The reversal of 646666040 is 40666646.

646666040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 646665985 and 646666003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646666049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 150725 + ... + 154955.

It is an arithmetic number, because the mean of its divisors is an integer number (45491355).

Almost surely, 2^646666040 is an apocalyptic number.

It is an amenable number.

646666040 is an abundant number, since it is smaller than the sum of its proper divisors (809057320).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646666040 is a wasteful number, since it uses less digits than its factorization.

646666040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8063 (or 8059 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 38.

The square root of 646666040 is about 25429.6291754323. The cubic root of 646666040 is about 864.7555369627.

The spelling of 646666040 in words is "six hundred forty-six million, six hundred sixty-six thousand, forty".