6561226660188 has 144 divisors (see below), whose sum is σ = 16390575565056. Its totient is φ = 2041552128000.

The previous prime is 6561226660187. The next prime is 6561226660193. The reversal of 6561226660188 is 8810666221656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561226660187) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 332187313 + ... + 332207063.

It is an arithmetic number, because the mean of its divisors is an integer number (113823441424).

Almost surely, 2^{6561226660188} 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 6561226660188, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8195287782528).

6561226660188 is an abundant number, since it is smaller than the sum of its proper divisors (9829348904868).

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

6561226660188 is a wasteful number, since it uses less digits than its factorization.

6561226660188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21064 (or 21039 counting only the distinct ones).

The product of its (nonzero) digits is 9953280, while the sum is 57.

The spelling of 6561226660188 in words is "six trillion, five hundred sixty-one billion, two hundred twenty-six million, six hundred sixty thousand, one hundred eighty-eight".