66721724045 has 8 divisors (see below), whose sum is σ = 82826967960. Its totient is φ = 51536779840.

The previous prime is 66721724033. The next prime is 66721724051. The reversal of 66721724045 is 54042712766.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3329059204 + 63392664841 = 57698^2 + 251779^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66721724045 - 2¹⁰ = 66721723021 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66721723987 and 66721724005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230074766 + ... + 230075055.

It is an arithmetic number, because the mean of its divisors is an integer number (10353370995).

Almost surely, 2^66721724045 is an apocalyptic number.

It is an amenable number.

66721724045 is a deficient number, since it is larger than the sum of its proper divisors (16105243915).

66721724045 is a wasteful number, since it uses less digits than its factorization.

66721724045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 460149855.

The product of its (nonzero) digits is 564480, while the sum is 44.

The spelling of 66721724045 in words is "sixty-six billion, seven hundred twenty-one million, seven hundred twenty-four thousand, forty-five".