646829440 has 32 divisors (see below), whose sum is σ = 1546328160. Its totient is φ = 258731520.

The previous prime is 646829431. The next prime is 646829459. The reversal of 646829440 is 44928646.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 504696 + ... + 505975.

It is an arithmetic number, because the mean of its divisors is an integer number (48322755).

Almost surely, 2^646829440 is an apocalyptic number.

It is an amenable number.

646829440 is an abundant number, since it is smaller than the sum of its proper divisors (899498720).

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

646829440 is a wasteful number, since it uses less digits than its factorization.

646829440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010690 (or 1010678 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 43.

The square root of 646829440 is about 25432.8417602123. The cubic root of 646829440 is about 864.8283664947.

The spelling of 646829440 in words is "six hundred forty-six million, eight hundred twenty-nine thousand, four hundred forty".