6561047500 has 120 divisors (see below), whose sum is σ = 16780628480. Its totient is φ = 2196936000.

The previous prime is 6561047489. The next prime is 6561047503. The reversal of 6561047500 is 57401656.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (6561047503) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 748141 + ... + 756859.

Almost surely, 2^6561047500 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 6561047500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8390314240).

6561047500 is an abundant number, since it is smaller than the sum of its proper divisors (10219580980).

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

6561047500 is a wasteful number, since it uses less digits than its factorization.

6561047500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8793 (or 8776 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 34.

The square root of 6561047500 is about 81000.2932093459. The cubic root of 6561047500 is about 1872.0799585219.

The spelling of 6561047500 in words is "six billion, five hundred sixty-one million, forty-seven thousand, five hundred".