66510106505 has 4 divisors (see below), whose sum is σ = 79812127812. Its totient is φ = 53208085200.

The previous prime is 66510106471. The next prime is 66510106529. The reversal of 66510106505 is 50560101566.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15955731856 + 50554374649 = 126316^2 + 224843^2 .

It is not a de Polignac number, because 66510106505 - 2¹⁰ = 66510105481 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 6651010646 + ... + 6651010655.

It is an arithmetic number, because the mean of its divisors is an integer number (19953031953).

Almost surely, 2^66510106505 is an apocalyptic number.

It is an amenable number.

66510106505 is a deficient number, since it is larger than the sum of its proper divisors (13302021307).

66510106505 is a wasteful number, since it uses less digits than its factorization.

66510106505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13302021306.

The product of its (nonzero) digits is 27000, while the sum is 35.

The spelling of 66510106505 in words is "sixty-six billion, five hundred ten million, one hundred six thousand, five hundred five".