6521599968 has 96 divisors (see below), whose sum is σ = 18784102176. Its totient is φ = 1968764928.

The previous prime is 6521599963. The next prime is 6521599979. The reversal of 6521599968 is 8699951256.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×6521599968² = 85062532285235202048, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6521599961) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16846 + ... + 115442.

It is an arithmetic number, because the mean of its divisors is an integer number (195667731).

Almost surely, 2^6521599968 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 6521599968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9392051088).

6521599968 is an abundant number, since it is smaller than the sum of its proper divisors (12262502208).

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

6521599968 is a wasteful number, since it uses less digits than its factorization.

6521599968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98676 (or 98668 counting only the distinct ones).

The product of its digits is 10497600, while the sum is 60.

The square root of 6521599968 is about 80756.4236949606. The cubic root of 6521599968 is about 1868.3205266568.

The spelling of 6521599968 in words is "six billion, five hundred twenty-one million, five hundred ninety-nine thousand, nine hundred sixty-eight".