646345308672 has 400 divisors, whose sum is σ = 2207821315392. Its totient is φ = 184414371840.

The previous prime is 646345308667. The next prime is 646345308691. The reversal of 646345308672 is 276803543646.

646345308672 is a `hidden beast` number, since 6 + 4 + 6 + 34 + 530 + 8 + 6 + 72 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 334719547 + ... + 334721477.

Almost surely, 2^646345308672 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 646345308672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1103910657696).

646345308672 is an abundant number, since it is smaller than the sum of its proper divisors (1561476006720).

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

646345308672 is a wasteful number, since it uses less digits than its factorization.

646345308672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3121 (or 3096 counting only the distinct ones).

The product of its (nonzero) digits is 17418240, while the sum is 54.

The spelling of 646345308672 in words is "six hundred forty-six billion, three hundred forty-five million, three hundred eight thousand, six hundred seventy-two".