641863740 has 144 divisors (see below), whose sum is σ = 2101855392. Its totient is φ = 145926144.

The previous prime is 641863727. The next prime is 641863811. The reversal of 641863740 is 47368146.

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, 684552 + ... + 685488.

It is an arithmetic number, because the mean of its divisors is an integer number (14596218).

Almost surely, 2^641863740 is an apocalyptic number.

641863740 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 641863740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1050927696).

641863740 is an abundant number, since it is smaller than the sum of its proper divisors (1459991652).

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

641863740 is a wasteful number, since it uses less digits than its factorization.

641863740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1196 (or 1187 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 39.

The square root of 641863740 is about 25335.0298993311. The cubic root of 641863740 is about 862.6095874197.

The spelling of 641863740 in words is "six hundred forty-one million, eight hundred sixty-three thousand, seven hundred forty".