6556538520 has 576 divisors, whose sum is σ = 26188081920. Its totient is φ = 1446149376.

The previous prime is 6556538519. The next prime is 6556538531. The reversal of 6556538520 is 258356556.

6556538520 is a `hidden beast` number, since 6 + 5 + 565 + 3 + 85 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 78994399 + ... + 78994481.

It is an arithmetic number, because the mean of its divisors is an integer number (45465420).

Almost surely, 2^6556538520 is an apocalyptic number.

6556538520 is a gapful number since it is divisible by the number (60) 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 6556538520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13094040960).

6556538520 is an abundant number, since it is smaller than the sum of its proper divisors (19631543400).

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

6556538520 is an equidigital number, since it uses as much as digits as its factorization.

6556538520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 1080000, while the sum is 45.

The square root of 6556538520 is about 80972.4553166075. The cubic root of 6556538520 is about 1871.6510074274.

The spelling of 6556538520 in words is "six billion, five hundred fifty-six million, five hundred thirty-eight thousand, five hundred twenty".