646530621768 has 160 divisors (see below), whose sum is σ = 1818109022400. Its totient is φ = 214652011392.

The previous prime is 646530621761. The next prime is 646530621787. The reversal of 646530621768 is 867126035646.

646530621768 is a `hidden beast` number, since 6 + 4 + 6 + 5 + 3 + 0 + 621 + 7 + 6 + 8 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (646530621761) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 375234555 + ... + 375236277.

It is an arithmetic number, because the mean of its divisors is an integer number (11363181390).

Almost surely, 2^646530621768 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 646530621768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (909054511200).

646530621768 is an abundant number, since it is smaller than the sum of its proper divisors (1171578400632).

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

646530621768 is a wasteful number, since it uses less digits than its factorization.

646530621768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3713 (or 3700 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 54.

The spelling of 646530621768 in words is "six hundred forty-six billion, five hundred thirty million, six hundred twenty-one thousand, seven hundred sixty-eight".