646356672 has 336 divisors, whose sum is σ = 2174565120. Its totient is φ = 188863488.

The previous prime is 646356661. The next prime is 646356691. The reversal of 646356672 is 276653646.

646356672 is a `hidden beast` number, since 6 + 4 + 635 + 6 + 6 + 7 + 2 = 666.

Its product of digits (1088640) is a multiple of the sum of its prime divisors (180).

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 47 ways as a sum of consecutive naturals, for example, 4649979 + ... + 4650117.

It is an arithmetic number, because the mean of its divisors is an integer number (6471920).

Almost surely, 2^646356672 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 646356672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1087282560).

646356672 is an abundant number, since it is smaller than the sum of its proper divisors (1528208448).

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

646356672 is a wasteful number, since it uses less digits than its factorization.

646356672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 202 (or 180 counting only the distinct ones).

The product of its digits is 1088640, while the sum is 45.

The square root of 646356672 is about 25423.5456221197. The cubic root of 646356672 is about 864.6176139608.

The spelling of 646356672 in words is "six hundred forty-six million, three hundred fifty-six thousand, six hundred seventy-two".