641852640 has 384 divisors, whose sum is σ = 2641766400. Its totient is φ = 143493120.

The previous prime is 641852639. The next prime is 641852641. The reversal of 641852640 is 46258146.

641852640 is a `hidden beast` number, since 6 + 4 + 1 + 8 + 5 + 2 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (641852639) and next prime (641852641).

It is a super-2 number, since 2×641852640² = 823949622949939200, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 641852595 and 641852604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641852641) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 617241 + ... + 618279.

It is an arithmetic number, because the mean of its divisors is an integer number (6879600).

Almost surely, 2^641852640 is an apocalyptic number.

641852640 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 641852640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1320883200).

641852640 is an abundant number, since it is smaller than the sum of its proper divisors (1999913760).

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

641852640 is a wasteful number, since it uses less digits than its factorization.

641852640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1087 (or 1073 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 641852640 is about 25334.8108341073. The cubic root of 641852640 is about 862.6046149097.

The spelling of 641852640 in words is "six hundred forty-one million, eight hundred fifty-two thousand, six hundred forty".