646921144800 has 720 divisors, whose sum is σ = 2708237724192. Its totient is φ = 147209011200.

The previous prime is 646921144747. The next prime is 646921144801. The reversal of 646921144800 is 8441129646.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646921144801) by changing a digit.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 105685740 + ... + 105691860.

Almost surely, 2^646921144800 is an apocalyptic number.

646921144800 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 646921144800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1354118862096).

646921144800 is an abundant number, since it is smaller than the sum of its proper divisors (2061316579392).

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

646921144800 is a wasteful number, since it uses less digits than its factorization.

646921144800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6393 (or 6371 counting only the distinct ones).

The product of its (nonzero) digits is 331776, while the sum is 45.

The spelling of 646921144800 in words is "six hundred forty-six billion, nine hundred twenty-one million, one hundred forty-four thousand, eight hundred".