66777997425 has 24 divisors (see below), whose sum is σ = 111961316160. Its totient is φ = 35113310400.

The previous prime is 66777997397. The next prime is 66777997441. The reversal of 66777997425 is 52479977766.

It is not a de Polignac number, because 66777997425 - 2⁶ = 66777997361 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 66777997425.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 6264910 + ... + 6275559.

It is an arithmetic number, because the mean of its divisors is an integer number (4665054840).

Almost surely, 2^66777997425 is an apocalyptic number.

It is an amenable number.

66777997425 is a deficient number, since it is larger than the sum of its proper divisors (45183318735).

66777997425 is a wasteful number, since it uses less digits than its factorization.

66777997425 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12540553 (or 12540548 counting only the distinct ones).

The product of its digits is 280052640, while the sum is 69.

The spelling of 66777997425 in words is "sixty-six billion, seven hundred seventy-seven million, nine hundred ninety-seven thousand, four hundred twenty-five".