66433720320 has 896 divisors, whose sum is σ = 265734881280. Its totient is φ = 15606743040.

The previous prime is 66433720273. The next prime is 66433720321. The reversal of 66433720320 is 2302733466.

66433720320 is a `hidden beast` number, since 6 + 643 + 3 + 7 + 2 + 0 + 3 + 2 + 0 = 666.

It is a harmonic number, since the harmonic mean of its divisors is an integer.

66433720320 is an admirable number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (66433720321) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 523100097 + ... + 523100223.

Almost surely, 2^66433720320 is an apocalyptic number.

66433720320 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 66433720320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132867440640).

66433720320 is an abundant number, since it is smaller than the sum of its proper divisors (199301160960).

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

66433720320 is a wasteful number, since it uses less digits than its factorization.

66433720320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 36.

The spelling of 66433720320 in words is "sixty-six billion, four hundred thirty-three million, seven hundred twenty thousand, three hundred twenty".