66931975712640 has 256 divisors, whose sum is σ = 225951654600000. Its totient is φ = 16794431520768.

The previous prime is 66931975712611. The next prime is 66931975712669. The reversal of 66931975712640 is 4621757913966.

It is an interprime number because it is at equal distance from previous prime (66931975712611) and next prime (66931975712669).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 131906136 + ... + 132412584.

Almost surely, 2^{66931975712640} is an apocalyptic number.

66931975712640 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 66931975712640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112975827300000).

66931975712640 is an abundant number, since it is smaller than the sum of its proper divisors (159019678887360).

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

66931975712640 is a wasteful number, since it uses less digits than its factorization.

66931975712640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 510537 (or 510525 counting only the distinct ones).

The product of its (nonzero) digits is 102876480, while the sum is 66.

The spelling of 66931975712640 in words is "sixty-six trillion, nine hundred thirty-one billion, nine hundred seventy-five million, seven hundred twelve thousand, six hundred forty".