66705521505 has 32 divisors (see below), whose sum is σ = 124571049984. Its totient is φ = 29845142976.

The previous prime is 66705521501. The next prime is 66705521507. The reversal of 66705521505 is 50512550766.

It is a happy number.

It is not a de Polignac number, because 66705521505 - 2² = 66705521501 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66705521501) 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 31 ways as a sum of consecutive naturals, for example, 6753477 + ... + 6763346.

It is an arithmetic number, because the mean of its divisors is an integer number (3892845312).

Almost surely, 2^66705521505 is an apocalyptic number.

It is an amenable number.

66705521505 is a deficient number, since it is larger than the sum of its proper divisors (57865528479).

66705521505 is a wasteful number, since it uses less digits than its factorization.

66705521505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13516885.

The product of its (nonzero) digits is 315000, while the sum is 42.

The spelling of 66705521505 in words is "sixty-six billion, seven hundred five million, five hundred twenty-one thousand, five hundred five".