66825544320 has 768 divisors, whose sum is σ = 251496161280. Its totient is φ = 16935505920.

The previous prime is 66825544319. The next prime is 66825544321. The reversal of 66825544320 is 2344552866.

66825544320 is a `hidden beast` number, since 6 + 6 + 82 + 5 + 544 + 3 + 20 = 666.

It is an interprime number because it is at equal distance from previous prime (66825544319) and next prime (66825544321).

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

It is not an unprimeable number, because it can be changed into a prime (66825544321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 400152877 + ... + 400153043.

It is an arithmetic number, because the mean of its divisors is an integer number (327468960).

Almost surely, 2^66825544320 is an apocalyptic number.

66825544320 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 66825544320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125748080640).

66825544320 is an abundant number, since it is smaller than the sum of its proper divisors (184670616960).

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

66825544320 is a wasteful number, since it uses less digits than its factorization.

66825544320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 315 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 1382400, while the sum is 45.

The spelling of 66825544320 in words is "sixty-six billion, eight hundred twenty-five million, five hundred forty-four thousand, three hundred twenty".