641600 has 42 divisors (see below), whose sum is σ = 1582674. Its totient is φ = 256000.

The previous prime is 641581. The next prime is 641623. The reversal of 641600 is 6146.

It is a Cunningham number, because it is equal to 801²-1.

It can be written as a sum of positive squares in 3 ways, for example, as 200704 + 440896 = 448^2 + 664^2 .

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 641600.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1400 + ... + 1800.

2⁶⁴¹⁶⁰⁰ 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 641600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (791337).

641600 is an abundant number, since it is smaller than the sum of its proper divisors (941074).

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

641600 is a wasteful number, since it uses less digits than its factorization.

641600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 423 (or 408 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 641600 is about 800.9993757800. Note that the first 3 decimals coincide. The cubic root of 641600 is about 86.2491423285.

Adding to 641600 its reverse (6146), we get a palindrome (647746).

It can be divided in two parts, 64 and 1600, that multiplied together give a square (102400 = 320²).

The spelling of 641600 in words is "six hundred forty-one thousand, six hundred".