646666344 has 48 divisors (see below), whose sum is σ = 1827540000. Its totient is φ = 206182944.

The previous prime is 646666313. The next prime is 646666351. The reversal of 646666344 is 443666646.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 646666344.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 193594 + ... + 196905.

It is an arithmetic number, because the mean of its divisors is an integer number (38073750).

Almost surely, 2^646666344 is an apocalyptic number.

It is an amenable number.

646666344 is an abundant number, since it is smaller than the sum of its proper divisors (1180873656).

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

646666344 is a wasteful number, since it uses less digits than its factorization.

646666344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390534 (or 390527 counting only the distinct ones).

The product of its digits is 1492992, while the sum is 45.

The square root of 646666344 is about 25429.6351527111. The cubic root of 646666344 is about 864.7556724709.

The spelling of 646666344 in words is "six hundred forty-six million, six hundred sixty-six thousand, three hundred forty-four".