6421839660 has 288 divisors, whose sum is σ = 21058652160. Its totient is φ = 1580198400.

The previous prime is 6421839653. The next prime is 6421839661. The reversal of 6421839660 is 669381246.

6421839660 is a `hidden beast` number, since 6 + 421 + 83 + 96 + 60 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (6421839661) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 14899645 + ... + 14900075.

It is an arithmetic number, because the mean of its divisors is an integer number (73120320).

Almost surely, 2^6421839660 is an apocalyptic number.

6421839660 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 6421839660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10529326080).

6421839660 is an abundant number, since it is smaller than the sum of its proper divisors (14636812500).

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

6421839660 is a wasteful number, since it uses less digits than its factorization.

6421839660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589 (or 584 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 6421839660 is about 80136.3816253267. The cubic root of 6421839660 is about 1858.7450257928.

The spelling of 6421839660 in words is "six billion, four hundred twenty-one million, eight hundred thirty-nine thousand, six hundred sixty".