66645790848 has 384 divisors, whose sum is σ = 243434505600. Its totient is φ = 17575833600.

The previous prime is 66645790811. The next prime is 66645790853. The reversal of 66645790848 is 84809754666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×66645790848² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4080298 + ... + 4096598.

It is an arithmetic number, because the mean of its divisors is an integer number (633944025).

Almost surely, 2^66645790848 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66645790848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121717252800).

66645790848 is an abundant number, since it is smaller than the sum of its proper divisors (176788714752).

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

66645790848 is a wasteful number, since it uses less digits than its factorization.

66645790848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16357 (or 16326 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 63.

The spelling of 66645790848 in words is "sixty-six billion, six hundred forty-five million, seven hundred ninety thousand, eight hundred forty-eight".