66906328320 has 576 divisors, whose sum is σ = 257791242240. Its totient is φ = 16333996032.

The previous prime is 66906328297. The next prime is 66906328337. The reversal of 66906328320 is 2382360966.

66906328320 is a `hidden beast` number, since 6 + 6 + 9 + 0 + 632 + 8 + 3 + 2 + 0 = 666.

66906328320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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, 61550817 + ... + 61551903.

It is an arithmetic number, because the mean of its divisors is an integer number (447554240).

Almost surely, 2^66906328320 is an apocalyptic number.

66906328320 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 66906328320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128895621120).

66906328320 is an abundant number, since it is smaller than the sum of its proper divisors (190884913920).

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

66906328320 is a wasteful number, since it uses less digits than its factorization.

66906328320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1267 (or 1247 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 45.

The spelling of 66906328320 in words is "sixty-six billion, nine hundred six million, three hundred twenty-eight thousand, three hundred twenty".