66723500672 has 128 divisors (see below), whose sum is σ = 142553466000. Its totient is φ = 31046270976.

The previous prime is 66723500671. The next prime is 66723500749. The reversal of 66723500672 is 27600532766.

It can be written as a sum of positive squares in 8 ways, for example, as 59290302016 + 7433198656 = 243496^2 + 86216^2 .

It is a tau number, because it is divible by the number of its divisors (128).

It is not an unprimeable number, because it can be changed into a prime (66723500671) 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, 14968268 + ... + 14972724.

Almost surely, 2^66723500672 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 66723500672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (71276733000).

66723500672 is an abundant number, since it is smaller than the sum of its proper divisors (75829965328).

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

66723500672 is a wasteful number, since it uses less digits than its factorization.

66723500672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4646 (or 4634 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 44.

The spelling of 66723500672 in words is "sixty-six billion, seven hundred twenty-three million, five hundred thousand, six hundred seventy-two".