66516203565 has 64 divisors (see below), whose sum is σ = 138287001600. Its totient is φ = 29700240192.

The previous prime is 66516203563. The next prime is 66516203617. The reversal of 66516203565 is 56530261566.

66516203565 is a `hidden beast` number, since 6 + 65 + 1 + 6 + 20 + 3 + 565 = 666.

It is not a de Polignac number, because 66516203565 - 2¹ = 66516203563 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 66516203565.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66516203563) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 777825 + ... + 859094.

It is an arithmetic number, because the mean of its divisors is an integer number (2160734400).

Almost surely, 2^66516203565 is an apocalyptic number.

It is an amenable number.

66516203565 is an abundant number, since it is smaller than the sum of its proper divisors (71770798035).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66516203565 is a wasteful number, since it uses less digits than its factorization.

66516203565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636983 (or 1636977 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 45.

The spelling of 66516203565 in words is "sixty-six billion, five hundred sixteen million, two hundred three thousand, five hundred sixty-five".