66723311729 has 4 divisors (see below), whose sum is σ = 67371110976. Its totient is φ = 66075512484.

The previous prime is 66723311671. The next prime is 66723311789. The reversal of 66723311729 is 92711332766.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66723311729 - 2²⁴ = 66706534513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66723311789) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 323899469 + ... + 323899674.

It is an arithmetic number, because the mean of its divisors is an integer number (16842777744).

Almost surely, 2^66723311729 is an apocalyptic number.

It is an amenable number.

66723311729 is a deficient number, since it is larger than the sum of its proper divisors (647799247).

66723311729 is a wasteful number, since it uses less digits than its factorization.

66723311729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 647799246.

The product of its digits is 571536, while the sum is 47.

The spelling of 66723311729 in words is "sixty-six billion, seven hundred twenty-three million, three hundred eleven thousand, seven hundred twenty-nine".