66128865075 has 384 divisors, whose sum is σ = 154656768000. Its totient is φ = 27525173760.

The previous prime is 66128865067. The next prime is 66128865079. The reversal of 66128865075 is 57056882166.

66128865075 is a `hidden beast` number, since 6 + 6 + 128 + 8 + 6 + 507 + 5 = 666.

It is not a de Polignac number, because 66128865075 - 2³ = 66128865067 is a prime.

It is a super-2 number, since 2×66128865075² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66128865079) by changing a digit.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 382247689 + ... + 382247861.

It is an arithmetic number, because the mean of its divisors is an integer number (402752000).

Almost surely, 2^66128865075 is an apocalyptic number.

66128865075 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66128865075 is an abundant number, since it is smaller than the sum of its proper divisors (88527902925).

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

66128865075 is a wasteful number, since it uses less digits than its factorization.

66128865075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 328 counting only the distinct ones).

The product of its (nonzero) digits is 4838400, while the sum is 54.

The spelling of 66128865075 in words is "sixty-six billion, one hundred twenty-eight million, eight hundred sixty-five thousand, seventy-five".