66525666779 has 24 divisors (see below), whose sum is σ = 78780475200. Its totient is φ = 55802799360.

The previous prime is 66525666773. The next prime is 66525666797. The reversal of 66525666779 is 97766652566.

It is not a de Polignac number, because 66525666779 - 2⁸ = 66525666523 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66525666773) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4596947 + ... + 4611395.

It is an arithmetic number, because the mean of its divisors is an integer number (3282519800).

Almost surely, 2^66525666779 is an apocalyptic number.

66525666779 is a deficient number, since it is larger than the sum of its proper divisors (12254808421).

66525666779 is a wasteful number, since it uses less digits than its factorization.

66525666779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17411 (or 17400 counting only the distinct ones).

The product of its digits is 171460800, while the sum is 65.

The spelling of 66525666779 in words is "sixty-six billion, five hundred twenty-five million, six hundred sixty-six thousand, seven hundred seventy-nine".