It is the 20-th Catalan number.
It is an unprimeable number.
Almost surely, 26564120420 is an apocalyptic number.
6564120420 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 6564120420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12355338240).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
6564120420 is a wasteful number, since it uses less digits than its factorization.
6564120420 is an odious number, because the sum of its binary digits is odd.
The square root of 6564120420 is about 81019.2595621560. The cubic root of 6564120420 is about 1872.3721808672.
The spelling of 6564120420 in words is "six billion, five hundred sixty-four million, one hundred twenty thousand, four hundred twenty".