66706657625 has 16 divisors (see below), whose sum is σ = 83258233344. Its totient is φ = 53359990000.

The previous prime is 66706657621. The next prime is 66706657631. The reversal of 66706657625 is 52675660766.

It is not a de Polignac number, because 66706657625 - 2² = 66706657621 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66706657621) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1646360 + ... + 1686390.

It is an arithmetic number, because the mean of its divisors is an integer number (5203639584).

Almost surely, 2^66706657625 is an apocalyptic number.

It is an amenable number.

66706657625 is a deficient number, since it is larger than the sum of its proper divisors (16551575719).

66706657625 is a wasteful number, since it uses less digits than its factorization.

66706657625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53377 (or 53367 counting only the distinct ones).

The product of its (nonzero) digits is 19051200, while the sum is 56.

The spelling of 66706657625 in words is "sixty-six billion, seven hundred six million, six hundred fifty-seven thousand, six hundred twenty-five".