66177765638545 has 16 divisors (see below), whose sum is σ = 87473805674112. Its totient is φ = 47662009493760.

The previous prime is 66177765638513. The next prime is 66177765638597. The reversal of 66177765638545 is 54583656777166.

It is not a de Polignac number, because 66177765638545 - 2⁵ = 66177765638513 is a prime.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 5840926872 + ... + 5840938201.

It is an arithmetic number, because the mean of its divisors is an integer number (5467112854632).

Almost surely, 2^{66177765638545} is an apocalyptic number.

It is an amenable number.

66177765638545 is a deficient number, since it is larger than the sum of its proper divisors (21296040035567).

66177765638545 is a wasteful number, since it uses less digits than its factorization.

66177765638545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11681865192.

The product of its digits is 5334336000, while the sum is 76.

The spelling of 66177765638545 in words is "sixty-six trillion, one hundred seventy-seven billion, seven hundred sixty-five million, six hundred thirty-eight thousand, five hundred forty-five".