6561271542540 has 192 divisors, whose sum is σ = 21586948250112. Its totient is φ = 1468013260800.

The previous prime is 6561271542533. The next prime is 6561271542569. The reversal of 6561271542540 is 452451721656.

It is a self number, because there is not a number n which added to its sum of digits gives 6561271542540.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 54448555 + ... + 54568925.

It is an arithmetic number, because the mean of its divisors is an integer number (112432022136).

Almost surely, 2^{6561271542540} is an apocalyptic number.

6561271542540 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 6561271542540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10793474125056).

6561271542540 is an abundant number, since it is smaller than the sum of its proper divisors (15025676707572).

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

6561271542540 is a wasteful number, since it uses less digits than its factorization.

6561271542540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126760 (or 126758 counting only the distinct ones).

The product of its (nonzero) digits is 2016000, while the sum is 48.

The spelling of 6561271542540 in words is "six trillion, five hundred sixty-one billion, two hundred seventy-one million, five hundred forty-two thousand, five hundred forty".