66631680 has 192 divisors, whose sum is σ = 237837600. Its totient is φ = 17694720.

The previous prime is 66631673. The next prime is 66631717. The reversal of 66631680 is 8613666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 276360 + ... + 276600.

Almost surely, 2^66631680 is an apocalyptic number.

66631680 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 66631680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (118918800).

66631680 is an abundant number, since it is smaller than the sum of its proper divisors (171205920).

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

66631680 is a wasteful number, since it uses less digits than its factorization.

66631680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 66631680 is about 8162.8230410808. The cubic root of 66631680 is about 405.4091886350.

The spelling of 66631680 in words is "sixty-six million, six hundred thirty-one thousand, six hundred eighty".