66939125760 has 720 divisors, whose sum is σ = 261113302296. Its totient is φ = 16307453952.

The previous prime is 66939125741. The next prime is 66939125767. The reversal of 66939125760 is 6752193966.

66939125760 is a `hidden beast` number, since 6 + 69 + 3 + 9 + 1 + 2 + 576 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 40179400704 + 26759725056 = 200448^2 + 163584^2 .

It is a tau number, because it is divible by the number of its divisors (720).

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 = 66939125697 and 66939125706.

It is not an unprimeable number, because it can be changed into a prime (66939125767) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 690094032 + ... + 690094128.

Almost surely, 2^66939125760 is an apocalyptic number.

66939125760 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 66939125760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130556651148).

66939125760 is an abundant number, since it is smaller than the sum of its proper divisors (194174176536).

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

66939125760 is an frugal number, since it uses more digits than its factorization.

66939125760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 120 counting only the distinct ones).

The product of its (nonzero) digits is 3674160, while the sum is 54.

The spelling of 66939125760 in words is "sixty-six billion, nine hundred thirty-nine million, one hundred twenty-five thousand, seven hundred sixty".