66393976320 has 960 divisors, whose sum is σ = 277402245120. Its totient is φ = 14906032128.

The previous prime is 66393976303. The next prime is 66393976331. The reversal of 66393976320 is 2367939366.

66393976320 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 (960).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 344010144 + ... + 344010336.

It is an arithmetic number, because the mean of its divisors is an integer number (288960672).

Almost surely, 2^66393976320 is an apocalyptic number.

66393976320 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 66393976320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138701122560).

66393976320 is an abundant number, since it is smaller than the sum of its proper divisors (211008268800).

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

66393976320 is an equidigital number, since it uses as much as digits as its factorization.

66393976320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 289 counting only the distinct ones).

The product of its (nonzero) digits is 6613488, while the sum is 54.

The spelling of 66393976320 in words is "sixty-six billion, three hundred ninety-three million, nine hundred seventy-six thousand, three hundred twenty".