66338053681 has 4 divisors (see below), whose sum is σ = 66341484352. Its totient is φ = 66334623012.

The previous prime is 66338053679. The next prime is 66338053703. The reversal of 66338053681 is 18635083366.

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 66338053681 - 2¹ = 66338053679 is a prime.

It is a super-2 number, since 2×66338053681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66338053651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1686165 + ... + 1725058.

It is an arithmetic number, because the mean of its divisors is an integer number (16585371088).

Almost surely, 2^66338053681 is an apocalyptic number.

It is an amenable number.

66338053681 is a deficient number, since it is larger than the sum of its proper divisors (3430671).

66338053681 is a wasteful number, since it uses less digits than its factorization.

66338053681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3430670.

The product of its (nonzero) digits is 1866240, while the sum is 49.

The spelling of 66338053681 in words is "sixty-six billion, three hundred thirty-eight million, fifty-three thousand, six hundred eighty-one".