646752040 has 64 divisors (see below), whose sum is σ = 1626246720. Its totient is φ = 229440000.

The previous prime is 646752037. The next prime is 646752047. The reversal of 646752040 is 40257646.

It is a junction number, because it is equal to n+sod(n) for n = 646751987 and 646752005.

It is not an unprimeable number, because it can be changed into a prime (646752047) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 115 + ... + 35965.

It is an arithmetic number, because the mean of its divisors is an integer number (25410105).

Almost surely, 2^646752040 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646752040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (813123360).

646752040 is an abundant number, since it is smaller than the sum of its proper divisors (979494680).

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

646752040 is a wasteful number, since it uses less digits than its factorization.

646752040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35914 (or 35910 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 34.

The square root of 646752040 is about 25431.3200601149. The cubic root of 646752040 is about 864.7938698244.

The spelling of 646752040 in words is "six hundred forty-six million, seven hundred fifty-two thousand, forty".