6381987840 has 384 divisors, whose sum is σ = 23280566400. Its totient is φ = 1657405440.

The previous prime is 6381987839. The next prime is 6381987847. The reversal of 6381987840 is 487891836.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6381987847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11335399 + ... + 11335961.

It is an arithmetic number, because the mean of its divisors is an integer number (60626475).

Almost surely, 2^6381987840 is an apocalyptic number.

6381987840 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 6381987840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11640283200).

6381987840 is an abundant number, since it is smaller than the sum of its proper divisors (16898578560).

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

6381987840 is a wasteful number, since it uses less digits than its factorization.

6381987840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 640 (or 614 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

The square root of 6381987840 is about 79887.3446798678. The cubic root of 6381987840 is about 1854.8921251896.

The spelling of 6381987840 in words is "six billion, three hundred eighty-one million, nine hundred eighty-seven thousand, eight hundred forty".