6211817856 has 128 divisors (see below), whose sum is σ = 18447638400. Its totient is φ = 2057716224.

The previous prime is 6211817813. The next prime is 6211817869. The reversal of 6211817856 is 6587181126.

6211817856 is a `hidden beast` number, since 621 + 1 + 8 + 17 + 8 + 5 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×6211817856² = 77173362152240873472, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 557815 + ... + 568841.

It is an arithmetic number, because the mean of its divisors is an integer number (144122175).

Almost surely, 2^6211817856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6211817856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9223819200).

6211817856 is an abundant number, since it is smaller than the sum of its proper divisors (12235820544).

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

6211817856 is a wasteful number, since it uses less digits than its factorization.

6211817856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11213 (or 11195 counting only the distinct ones).

The product of its digits is 161280, while the sum is 45.

The square root of 6211817856 is about 78815.0864746084. The cubic root of 6211817856 is about 1838.2570388323.

The spelling of 6211817856 in words is "six billion, two hundred eleven million, eight hundred seventeen thousand, eight hundred fifty-six".