66056005605565 has 4 divisors (see below), whose sum is σ = 79267206726684. Its totient is φ = 52844804484448.

The previous prime is 66056005605517. The next prime is 66056005605587. The reversal of 66056005605565 is 56550650065066.

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 17771671197316 + 48284334408249 = 4215646^2 + 6948693^2 .

It is a cyclic number.

It is not a de Polignac number, because 66056005605565 - 2⁷ = 66056005605437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6605600560552 + ... + 6605600560561.

It is an arithmetic number, because the mean of its divisors is an integer number (19816801681671).

Almost surely, 2^{66056005605565} is an apocalyptic number.

It is an amenable number.

66056005605565 is a deficient number, since it is larger than the sum of its proper divisors (13211201121119).

66056005605565 is a wasteful number, since it uses less digits than its factorization.

66056005605565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13211201121118.

The product of its (nonzero) digits is 24300000, while the sum is 55.

The spelling of 66056005605565 in words is "sixty-six trillion, fifty-six billion, five million, six hundred five thousand, five hundred sixty-five".