66757772161 has 8 divisors (see below), whose sum is σ = 67084012800. Its totient is φ = 66431771952.

The previous prime is 66757772129. The next prime is 66757772177. The reversal of 66757772161 is 16127775766.

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 66757772161 - 2⁵ = 66757772129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66757772261) 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, 509706 + ... + 627148.

It is an arithmetic number, because the mean of its divisors is an integer number (8385501600).

Almost surely, 2^66757772161 is an apocalyptic number.

It is an amenable number.

66757772161 is a deficient number, since it is larger than the sum of its proper divisors (326240639).

66757772161 is a wasteful number, since it uses less digits than its factorization.

66757772161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120215.

The product of its digits is 5186160, while the sum is 55.

The spelling of 66757772161 in words is "sixty-six billion, seven hundred fifty-seven million, seven hundred seventy-two thousand, one hundred sixty-one".