66709536497 has 4 divisors (see below), whose sum is σ = 67189461360. Its totient is φ = 66229611636.

The previous prime is 66709536473. The next prime is 66709536589. The reversal of 66709536497 is 79463590766.

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 66709536497 - 2¹² = 66709532401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66709526497) 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, 239962223 + ... + 239962500.

It is an arithmetic number, because the mean of its divisors is an integer number (16797365340).

Almost surely, 2^66709536497 is an apocalyptic number.

It is an amenable number.

66709536497 is a deficient number, since it is larger than the sum of its proper divisors (479924863).

66709536497 is a wasteful number, since it uses less digits than its factorization.

66709536497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479924862.

The product of its (nonzero) digits is 51438240, while the sum is 62.

The spelling of 66709536497 in words is "sixty-six billion, seven hundred nine million, five hundred thirty-six thousand, four hundred ninety-seven".