66107761600056 has 128 divisors (see below), whose sum is σ = 180824767200000. Its totient is φ = 19973678376960.

The previous prime is 66107761600051. The next prime is 66107761600063. The reversal of 66107761600056 is 65000616770166.

It is a super-4 number, since 4×66107761600056⁴ (a number of 56 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 66107761599981 and 66107761600008.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66107761600051) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1763372160 + ... + 1763409648.

It is an arithmetic number, because the mean of its divisors is an integer number (1412693493750).

Almost surely, 2^{66107761600056} is an apocalyptic number.

66107761600056 is a gapful number since it is divisible by the number (66) 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 66107761600056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90412383600000).

66107761600056 is an abundant number, since it is smaller than the sum of its proper divisors (114717005599944).

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

66107761600056 is a wasteful number, since it uses less digits than its factorization.

66107761600056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56997 (or 56993 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 51.

The spelling of 66107761600056 in words is "sixty-six trillion, one hundred seven billion, seven hundred sixty-one million, six hundred thousand, fifty-six".