66729716591 has 8 divisors (see below), whose sum is σ = 67382928000. Its totient is φ = 66079684440.

The previous prime is 66729716579. The next prime is 66729716597. The reversal of 66729716591 is 19561792766.

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

It is a cyclic number.

It is not a de Polignac number, because 66729716591 - 2¹⁸ = 66729454447 is a prime.

It is a super-2 number, since 2×66729716591² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66729716591.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66729716597) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 752621 + ... + 836598.

It is an arithmetic number, because the mean of its divisors is an integer number (8422866000).

Almost surely, 2^66729716591 is an apocalyptic number.

66729716591 is a deficient number, since it is larger than the sum of its proper divisors (653211409).

66729716591 is a wasteful number, since it uses less digits than its factorization.

66729716591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1589629.

The product of its digits is 8573040, while the sum is 59.

The spelling of 66729716591 in words is "sixty-six billion, seven hundred twenty-nine million, seven hundred sixteen thousand, five hundred ninety-one".