641204400 has 120 divisors (see below), whose sum is σ = 2162173120. Its totient is φ = 161982720.

The previous prime is 641204387. The next prime is 641204401. The reversal of 641204400 is 4402146.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×641204400² = 822286165158720000, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (641204401) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8739 + ... + 36861.

Almost surely, 2^641204400 is an apocalyptic number.

641204400 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 641204400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1081086560).

641204400 is an abundant number, since it is smaller than the sum of its proper divisors (1520968720).

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

641204400 is a wasteful number, since it uses less digits than its factorization.

641204400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28163 (or 28152 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 641204400 is about 25322.0141378999. The cubic root of 641204400 is about 862.3141208342.

Adding to 641204400 its reverse (4402146), we get a palindrome (645606546).

The spelling of 641204400 in words is "six hundred forty-one million, two hundred four thousand, four hundred".