641944800 has 432 divisors, whose sum is σ = 2651830272. Its totient is φ = 143078400.

The previous prime is 641944759. The next prime is 641944817. The reversal of 641944800 is 8449146.

It is a happy number.

641944800 is a `hidden beast` number, since 641 + 9 + 4 + 4 + 8 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2368665 + ... + 2368935.

It is an arithmetic number, because the mean of its divisors is an integer number (6138496).

Almost surely, 2^641944800 is an apocalyptic number.

641944800 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 641944800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1325915136).

641944800 is an abundant number, since it is smaller than the sum of its proper divisors (2009885472).

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

641944800 is a wasteful number, since it uses less digits than its factorization.

641944800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 351 (or 335 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 641944800 is about 25336.6296101119. The cubic root of 641944800 is about 862.6458984442.

The spelling of 641944800 in words is "six hundred forty-one million, nine hundred forty-four thousand, eight hundred".