66155517054989 has 16 divisors (see below), whose sum is σ = 67649605297920. Its totient is φ = 64678397784000.

The previous prime is 66155517054931. The next prime is 66155517055003. The reversal of 66155517054989 is 98945071555166.

It is not a de Polignac number, because 66155517054989 - 2³⁶ = 66086797578253 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66155517054889) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16938239 + ... + 20474739.

It is an arithmetic number, because the mean of its divisors is an integer number (4228100331120).

Almost surely, 2^{66155517054989} is an apocalyptic number.

It is an amenable number.

66155517054989 is a deficient number, since it is larger than the sum of its proper divisors (1494088242931).

66155517054989 is a wasteful number, since it uses less digits than its factorization.

66155517054989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3538900.

The product of its (nonzero) digits is 408240000, while the sum is 71.

The spelling of 66155517054989 in words is "sixty-six trillion, one hundred fifty-five billion, five hundred seventeen million, fifty-four thousand, nine hundred eighty-nine".