66561065511 has 8 divisors (see below), whose sum is σ = 89609719680. Its totient is φ = 43943227512.

The previous prime is 66561065509. The next prime is 66561065521. The reversal of 66561065511 is 11556016566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66561065511 - 2¹ = 66561065509 is a prime.

It is a super-2 number, since 2×66561065511² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66561065521) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 107703681 + ... + 107704298.

It is an arithmetic number, because the mean of its divisors is an integer number (11201214960).

Almost surely, 2^66561065511 is an apocalyptic number.

66561065511 is a deficient number, since it is larger than the sum of its proper divisors (23048654169).

66561065511 is a wasteful number, since it uses less digits than its factorization.

66561065511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215408085.

The product of its (nonzero) digits is 162000, while the sum is 42.

The spelling of 66561065511 in words is "sixty-six billion, five hundred sixty-one million, sixty-five thousand, five hundred eleven".