66502566 has 64 divisors (see below), whose sum is σ = 161864640. Its totient is φ = 20113920.

The previous prime is 66502561. The next prime is 66502567. The reversal of 66502566 is 66520566.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 66502566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66502561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 42046 + ... + 43598.

It is an arithmetic number, because the mean of its divisors is an integer number (2529135).

Almost surely, 2^66502566 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66502566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80932320).

66502566 is an abundant number, since it is smaller than the sum of its proper divisors (95362074).

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

66502566 is a wasteful number, since it uses less digits than its factorization.

66502566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1638 (or 1632 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The square root of 66502566 is about 8154.9105451869. The cubic root of 66502566 is about 405.1471618839.

It can be divided in two parts, 6650 and 2566, that added together give a square (9216 = 96²).

The spelling of 66502566 in words is "sixty-six million, five hundred two thousand, five hundred sixty-six".