66540027613 has 6 divisors (see below), whose sum is σ = 66576283646. Its totient is φ = 66503791032.

The previous prime is 66540027611. The next prime is 66540027637. The reversal of 66540027613 is 31672004566.

It can be written as a sum of positive squares in only one way, i.e., 42688931769 + 23851095844 = 206613^2 + 154438^2 .

It is not a de Polignac number, because 66540027613 - 2¹ = 66540027611 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66540027611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4347931 + ... + 4363207.

Almost surely, 2^66540027613 is an apocalyptic number.

It is an amenable number.

66540027613 is a deficient number, since it is larger than the sum of its proper divisors (36256033).

66540027613 is an frugal number, since it uses more digits than its factorization.

66540027613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19451 (or 17364 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 40.

The spelling of 66540027613 in words is "sixty-six billion, five hundred forty million, twenty-seven thousand, six hundred thirteen".