66910521231648 has 384 divisors, whose sum is σ = 198867529728000. Its totient is φ = 21882624906240.

The previous prime is 66910521231629. The next prime is 66910521231683. The reversal of 66910521231648 is 84613212501966.

66910521231648 is a `hidden beast` number, since 6 + 6 + 9 + 105 + 212 + 316 + 4 + 8 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 66910521231594 and 66910521231603.

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, 11459240313 + ... + 11459246151.

It is an arithmetic number, because the mean of its divisors is an integer number (517884192000).

Almost surely, 2^{66910521231648} 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 66910521231648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99433764864000).

66910521231648 is an abundant number, since it is smaller than the sum of its proper divisors (131957008496352).

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

66910521231648 is a wasteful number, since it uses less digits than its factorization.

66910521231648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6805 (or 6791 counting only the distinct ones).

The product of its (nonzero) digits is 3732480, while the sum is 54.

The spelling of 66910521231648 in words is "sixty-six trillion, nine hundred ten billion, five hundred twenty-one million, two hundred thirty-one thousand, six hundred forty-eight".