66666108326400 has 1440 divisors, whose sum is σ = 279219569428800. Its totient is φ = 15603956121600.

The previous prime is 66666108326383. The next prime is 66666108326401. The reversal of 66666108326400 is 462380166666.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (66666108326401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 992184006 + ... + 992251194.

It is an arithmetic number, because the mean of its divisors is an integer number (193902478770).

Almost surely, 2^{66666108326400} is an apocalyptic number.

66666108326400 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 66666108326400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (139609784714400).

66666108326400 is an abundant number, since it is smaller than the sum of its proper divisors (212553461102400).

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

66666108326400 is a wasteful number, since it uses less digits than its factorization.

66666108326400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67272 (or 67239 counting only the distinct ones).

The product of its (nonzero) digits is 8957952, while the sum is 54.

The spelling of 66666108326400 in words is "sixty-six trillion, six hundred sixty-six billion, one hundred eight million, three hundred twenty-six thousand, four hundred".