6641171856 has 400 divisors, whose sum is σ = 22588822080. Its totient is φ = 1861263360.

The previous prime is 6641171813. The next prime is 6641171879. The reversal of 6641171856 is 6581711466.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 16237380 + ... + 16237788.

Almost surely, 2^6641171856 is an apocalyptic number.

6641171856 is a gapful number since it is divisible by the number (66) 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 6641171856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11294411040).

6641171856 is an abundant number, since it is smaller than the sum of its proper divisors (15947650224).

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

6641171856 is a wasteful number, since it uses less digits than its factorization.

6641171856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524 (or 509 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 6641171856 is about 81493.3853512050. The cubic root of 6641171856 is about 1879.6698394109.

The spelling of 6641171856 in words is "six billion, six hundred forty-one million, one hundred seventy-one thousand, eight hundred fifty-six".