6521856880 has 640 divisors, whose sum is σ = 21598617600. Its totient is φ = 1806336000.

The previous prime is 6521856871. The next prime is 6521856919. The reversal of 6521856880 is 886581256.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 159069660 + ... + 159069700.

It is an arithmetic number, because the mean of its divisors is an integer number (33747840).

Almost surely, 2^6521856880 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 6521856880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10799308800).

6521856880 is an abundant number, since it is smaller than the sum of its proper divisors (15076760720).

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

6521856880 is a wasteful number, since it uses less digits than its factorization.

6521856880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134 (or 114 counting only the distinct ones).

The product of its (nonzero) digits is 921600, while the sum is 49.

The square root of 6521856880 is about 80758.0143391354. The cubic root of 6521856880 is about 1868.3450598830.

The spelling of 6521856880 in words is "six billion, five hundred twenty-one million, eight hundred fifty-six thousand, eight hundred eighty".