66138348182400 has 768 divisors, whose sum is σ = 260740644864000. Its totient is φ = 16275613409280.

The previous prime is 66138348182321. The next prime is 66138348182407. The reversal of 66138348182400 is 428184383166.

It is a happy number.

66138348182400 is a `hidden beast` number, since 6 + 6 + 1 + 3 + 83 + 4 + 81 + 82 + 400 = 666.

66138348182400 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×66138348182400² (a number of 28 digits) contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66138348182407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5749655049 + ... + 5749666551.

It is an arithmetic number, because the mean of its divisors is an integer number (339506048000).

Almost surely, 2^{66138348182400} is an apocalyptic number.

66138348182400 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 66138348182400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130370322432000).

66138348182400 is an abundant number, since it is smaller than the sum of its proper divisors (194602296681600).

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

66138348182400 is a wasteful number, since it uses less digits than its factorization.

66138348182400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16668 (or 16645 counting only the distinct ones).

The product of its (nonzero) digits is 5308416, while the sum is 54.

The spelling of 66138348182400 in words is "sixty-six trillion, one hundred thirty-eight billion, three hundred forty-eight million, one hundred eighty-two thousand, four hundred".