66686934935040 has 640 divisors, whose sum is σ = 244445384494080. Its totient is φ = 15192782143488.

The previous prime is 66686934935039. The next prime is 66686934935059. The reversal of 66686934935040 is 4053943968666.

It is a tau number, because it is divible by the number of its divisors (640).

It is a hoax number, since the sum of its digits (69) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 26265038091 + ... + 26265040629.

It is an arithmetic number, because the mean of its divisors is an integer number (381945913272).

Almost surely, 2^{66686934935040} is an apocalyptic number.

66686934935040 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 66686934935040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (122222692247040).

66686934935040 is an abundant number, since it is smaller than the sum of its proper divisors (177758449559040).

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

66686934935040 is a wasteful number, since it uses less digits than its factorization.

66686934935040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3982 (or 3966 counting only the distinct ones).

The product of its (nonzero) digits is 604661760, while the sum is 69.

The spelling of 66686934935040 in words is "sixty-six trillion, six hundred eighty-six billion, nine hundred thirty-four million, nine hundred thirty-five thousand, forty".