646766688 has 48 divisors (see below), whose sum is σ = 1787123520. Its totient is φ = 204241536.

The previous prime is 646766657. The next prime is 646766689. The reversal of 646766688 is 886667646.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646766689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175470 + ... + 179117.

It is an arithmetic number, because the mean of its divisors is an integer number (37231740).

Almost surely, 2^646766688 is an apocalyptic number.

It is an amenable number.

646766688 is an abundant number, since it is smaller than the sum of its proper divisors (1140356832).

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

646766688 is a wasteful number, since it uses less digits than its factorization.

646766688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354619 (or 354611 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 57.

The square root of 646766688 is about 25431.6080498265. The cubic root of 646766688 is about 864.8003985527.

The spelling of 646766688 in words is "six hundred forty-six million, seven hundred sixty-six thousand, six hundred eighty-eight".