66005105520 has 40 divisors (see below), whose sum is σ = 204615827856. Its totient is φ = 17601361408.

The previous prime is 66005105519. The next prime is 66005105521. The reversal of 66005105520 is 2550150066.

It is an interprime number because it is at equal distance from previous prime (66005105519) and next prime (66005105521).

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66005105521) 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 7 ways as a sum of consecutive naturals, for example, 137510397 + ... + 137510876.

Almost surely, 2^66005105520 is an apocalyptic number.

66005105520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66005105520 is an abundant number, since it is smaller than the sum of its proper divisors (138610722336).

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

66005105520 is a wasteful number, since it uses less digits than its factorization.

66005105520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275021289 (or 275021283 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

Adding to 66005105520 its reverse (2550150066), we get a palindrome (68555255586).

The spelling of 66005105520 in words is "sixty-six billion, five million, one hundred five thousand, five hundred twenty".