66654161661 has 8 divisors (see below), whose sum is σ = 88879377024. Its totient is φ = 44432527040.

The previous prime is 66654161641. The next prime is 66654161767. The reversal of 66654161661 is 16616145666.

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 66654161661 - 2⁹ = 66654161149 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 66654161661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66654161641) 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, 851445 + ... + 926426.

It is an arithmetic number, because the mean of its divisors is an integer number (11109922128).

Almost surely, 2^66654161661 is an apocalyptic number.

It is an amenable number.

66654161661 is a deficient number, since it is larger than the sum of its proper divisors (22225215363).

66654161661 is a wasteful number, since it uses less digits than its factorization.

66654161661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1790371.

The product of its digits is 933120, while the sum is 48.

The spelling of 66654161661 in words is "sixty-six billion, six hundred fifty-four million, one hundred sixty-one thousand, six hundred sixty-one".