6321561216 has 64 divisors (see below), whose sum is σ = 16834349280. Its totient is φ = 2101828608.

The previous prime is 6321561203. The next prime is 6321561227. The reversal of 6321561216 is 6121651236.

It is a tau number, because it is divible by the number of its divisors (64).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131715 + ... + 173181.

Almost surely, 2^6321561216 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 6321561216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8417174640).

6321561216 is an abundant number, since it is smaller than the sum of its proper divisors (10512788064).

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

6321561216 is a wasteful number, since it uses less digits than its factorization.

6321561216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41881 (or 41869 counting only the distinct ones).

The product of its digits is 12960, while the sum is 33.

The square root of 6321561216 is about 79508.2462138362. The cubic root of 6321561216 is about 1849.0193210943.

The spelling of 6321561216 in words is "six billion, three hundred twenty-one million, five hundred sixty-one thousand, two hundred sixteen".