66121260547584 has 640 divisors, whose sum is σ = 201068010823680. Its totient is φ = 19135542067200.

The previous prime is 66121260547583. The next prime is 66121260547649. The reversal of 66121260547584 is 48574506212166.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66121260547583) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5298596257 + ... + 5298608735.

It is an arithmetic number, because the mean of its divisors is an integer number (314168766912).

Almost surely, 2^{66121260547584} is an apocalyptic number.

66121260547584 is a gapful number since it is divisible by the number (64) 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 66121260547584, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100534005411840).

66121260547584 is an abundant number, since it is smaller than the sum of its proper divisors (134946750276096).

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

66121260547584 is a wasteful number, since it uses less digits than its factorization.

66121260547584 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12722 (or 12706 counting only the distinct ones).

The product of its (nonzero) digits is 19353600, while the sum is 57.

The spelling of 66121260547584 in words is "sixty-six trillion, one hundred twenty-one billion, two hundred sixty million, five hundred forty-seven thousand, five hundred eighty-four".