646138600 has 48 divisors (see below), whose sum is σ = 1506739500. Its totient is φ = 257687040.

The previous prime is 646138579. The next prime is 646138667. The reversal of 646138600 is 6831646.

It can be written as a sum of positive squares in 6 ways, for example, as 147331044 + 498807556 = 12138^2 + 22334^2 .

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, 65172 + ... + 74428.

Almost surely, 2^646138600 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 646138600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (753369750).

646138600 is an abundant number, since it is smaller than the sum of its proper divisors (860600900).

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

646138600 is a wasteful number, since it uses less digits than its factorization.

646138600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9622 (or 9613 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 646138600 is about 25419.2564800782. The cubic root of 646138600 is about 864.5203662599.

The spelling of 646138600 in words is "six hundred forty-six million, one hundred thirty-eight thousand, six hundred".