66687406188720 has 80 divisors (see below), whose sum is σ = 206735101797120. Its totient is φ = 17782951963392.

The previous prime is 66687406188677. The next prime is 66687406188727. The reversal of 66687406188720 is 2788160478666.

It is a tau number, because it is divible by the number of its divisors (80).

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 not an unprimeable number, because it can be changed into a prime (66687406188727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9327327 + ... + 14844993.

It is an arithmetic number, because the mean of its divisors is an integer number (2584188772464).

Almost surely, 2^{66687406188720} is an apocalyptic number.

66687406188720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66687406188720 is an abundant number, since it is smaller than the sum of its proper divisors (140047695608400).

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

66687406188720 is a wasteful number, since it uses less digits than its factorization.

66687406188720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5568042 (or 5568036 counting only the distinct ones).

The product of its (nonzero) digits is 260112384, while the sum is 69.

The spelling of 66687406188720 in words is "sixty-six trillion, six hundred eighty-seven billion, four hundred six million, one hundred eighty-eight thousand, seven hundred twenty".