66505661474 has 32 divisors (see below), whose sum is σ = 114560040960. Its totient is φ = 28364998032.

The previous prime is 66505661473. The next prime is 66505661479. The reversal of 66505661474 is 47416650566.

It is a super-4 number, since 4×66505661474⁴ (a number of 44 digits) contains 4444 as substring.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66505661473) 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 15 ways as a sum of consecutive naturals, for example, 6094307 + ... + 6105209.

It is an arithmetic number, because the mean of its divisors is an integer number (3580001280).

Almost surely, 2^66505661474 is an apocalyptic number.

66505661474 is a deficient number, since it is larger than the sum of its proper divisors (48054379486).

66505661474 is a wasteful number, since it uses less digits than its factorization.

66505661474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12974.

The product of its (nonzero) digits is 3628800, while the sum is 50.

The spelling of 66505661474 in words is "sixty-six billion, five hundred five million, six hundred sixty-one thousand, four hundred seventy-four".