66631968 has 162 divisors, whose sum is σ = 210876939. Its totient is φ = 19948032.

The previous prime is 66631963. The next prime is 66631979. The reversal of 66631968 is 86913666.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

66631968 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 5 ways, for example, as 37601424 + 29030544 = 6132^2 + 5388^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=5772.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (66631963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1800846 + ... + 1800882.

Almost surely, 2^66631968 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66631968

66631968 is an abundant number, since it is smaller than the sum of its proper divisors (144244971).

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

66631968 is a wasteful number, since it uses less digits than its factorization.

66631968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116 (or 55 counting only the distinct ones).

The product of its digits is 279936, while the sum is 45.

The square root of 66631968 is about 8162.8406820175. The cubic root of 66631968 is about 405.4097727299.

The spelling of 66631968 in words is "sixty-six million, six hundred thirty-one thousand, nine hundred sixty-eight".