66955687872 has 56 divisors (see below), whose sum is σ = 184855933056. Its totient is φ = 21348188928.

The previous prime is 66955687861. The next prime is 66955687873. The reversal of 66955687872 is 27878655966.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (69).

It is a junction number, because it is equal to n+sod(n) for n = 66955687797 and 66955687806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66955687873) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7576618 + ... + 7585449.

Almost surely, 2^66955687872 is an apocalyptic number.

It is an amenable number.

66955687872 is an abundant number, since it is smaller than the sum of its proper divisors (117900245184).

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

66955687872 is a wasteful number, since it uses less digits than its factorization.

66955687872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15162105 (or 15162095 counting only the distinct ones).

The product of its digits is 304819200, while the sum is 69.

The spelling of 66955687872 in words is "sixty-six billion, nine hundred fifty-five million, six hundred eighty-seven thousand, eight hundred seventy-two".