66645508763 has 4 divisors (see below), whose sum is σ = 66646442520. Its totient is φ = 66644575008.

The previous prime is 66645508757. The next prime is 66645508793. The reversal of 66645508763 is 36780554666.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66645508763 - 2¹⁰ = 66645507739 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66645508699 and 66645508708.

It is not an unprimeable number, because it can be changed into a prime (66645508723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350078 + ... + 505811.

It is an arithmetic number, because the mean of its divisors is an integer number (16661610630).

Almost surely, 2^66645508763 is an apocalyptic number.

66645508763 is a deficient number, since it is larger than the sum of its proper divisors (933757).

66645508763 is an equidigital number, since it uses as much as digits as its factorization.

66645508763 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 933756.

The product of its (nonzero) digits is 21772800, while the sum is 56.

The spelling of 66645508763 in words is "sixty-six billion, six hundred forty-five million, five hundred eight thousand, seven hundred sixty-three".