641185919640 has 768 divisors, whose sum is σ = 2554588108800. Its totient is φ = 136317468672.

The previous prime is 641185919611. The next prime is 641185919641. The reversal of 641185919640 is 46919581146.

641185919640 is a `hidden beast` number, since 6 + 4 + 1 + 1 + 8 + 591 + 9 + 6 + 40 = 666.

It is a super-2 number, since 2×641185919640² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (641185919641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 331704114 + ... + 331706046.

It is an arithmetic number, because the mean of its divisors is an integer number (3326286600).

Almost surely, 2^641185919640 is an apocalyptic number.

641185919640 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 641185919640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1277294054400).

641185919640 is an abundant number, since it is smaller than the sum of its proper divisors (1913402189160).

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

641185919640 is a wasteful number, since it uses less digits than its factorization.

641185919640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2136 (or 2129 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The spelling of 641185919640 in words is "six hundred forty-one billion, one hundred eighty-five million, nine hundred nineteen thousand, six hundred forty".