646925959680 has 2560 divisors, whose sum is σ = 3019966709760. Its totient is φ = 113706270720.

The previous prime is 646925959657. The next prime is 646925959703. The reversal of 646925959680 is 86959529646.

It is an interprime number because it is at equal distance from previous prime (646925959657) and next prime (646925959703).

It is a tau number, because it is divible by the number of its divisors (2560).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 255 ways as a sum of consecutive naturals, for example, 6280834509 + ... + 6280834611.

It is an arithmetic number, because the mean of its divisors is an integer number (1179674496).

Almost surely, 2^646925959680 is an apocalyptic number.

646925959680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 646925959680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1509983354880).

646925959680 is an abundant number, since it is smaller than the sum of its proper divisors (2373040750080).

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

646925959680 is a wasteful number, since it uses less digits than its factorization.

646925959680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 222 (or 206 counting only the distinct ones).

The product of its (nonzero) digits is 251942400, while the sum is 69.

The spelling of 646925959680 in words is "six hundred forty-six billion, nine hundred twenty-five million, nine hundred fifty-nine thousand, six hundred eighty".