66517819875 has 192 divisors, whose sum is σ = 139116257280. Its totient is φ = 30308256000.

The previous prime is 66517819871. The next prime is 66517819897. The reversal of 66517819875 is 57891871566.

It is not a de Polignac number, because 66517819875 - 2² = 66517819871 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66517819871) by changing a digit.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 10424436 + ... + 10430814.

It is an arithmetic number, because the mean of its divisors is an integer number (724563840).

Almost surely, 2^66517819875 is an apocalyptic number.

66517819875 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

66517819875 is an abundant number, since it is smaller than the sum of its proper divisors (72598437405).

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

66517819875 is a wasteful number, since it uses less digits than its factorization.

66517819875 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6467 (or 6454 counting only the distinct ones).

The product of its digits is 25401600, while the sum is 63.

The spelling of 66517819875 in words is "sixty-six billion, five hundred seventeen million, eight hundred nineteen thousand, eight hundred seventy-five".