641244240 has 240 divisors, whose sum is σ = 2650747008. Its totient is φ = 135281664.

The previous prime is 641244229. The next prime is 641244277. The reversal of 641244240 is 42442146.

It is a happy number.

641244240 is a `hidden beast` number, since 6 + 412 + 4 + 4 + 240 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×641244240² = 822388350666355200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 60627 + ... + 70413.

Almost surely, 2^641244240 is an apocalyptic number.

641244240 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 641244240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1325373504).

641244240 is an abundant number, since it is smaller than the sum of its proper divisors (2009502768).

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

641244240 is a wasteful number, since it uses less digits than its factorization.

641244240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9826 (or 9817 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 27.

The square root of 641244240 is about 25322.8007929613. The cubic root of 641244240 is about 862.3319798732.

Adding to 641244240 its reverse (42442146), we get a palindrome (683686386).

The spelling of 641244240 in words is "six hundred forty-one million, two hundred forty-four thousand, two hundred forty".