6561380387016 has 1440 divisors, whose sum is σ = 24478733359080. Its totient is φ = 1626515251200.

The previous prime is 6561380387011. The next prime is 6561380387033. The reversal of 6561380387016 is 6107830831656.

6561380387016 is a `hidden beast` number, since 6 + 5 + 613 + 8 + 0 + 3 + 8 + 7 + 0 + 16 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 150508306116 + 6410872080900 = 387954^2 + 2531970^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (6561380387011) by changing a digit.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 14232929026 + ... + 14232929486.

Almost surely, 2^{6561380387016} 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 6561380387016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12239366679540).

6561380387016 is an abundant number, since it is smaller than the sum of its proper divisors (17917352972064).

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

6561380387016 is a wasteful number, since it uses less digits than its factorization.

6561380387016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 605 (or 556 counting only the distinct ones).

The product of its (nonzero) digits is 4354560, while the sum is 54.

The spelling of 6561380387016 in words is "six trillion, five hundred sixty-one billion, three hundred eighty million, three hundred eighty-seven thousand, sixteen".