66765725525 has 6 divisors (see below), whose sum is σ = 82789499682. Its totient is φ = 53412580400.

The previous prime is 66765725519. The next prime is 66765725527. The reversal of 66765725525 is 52552756766.

It can be written as a sum of positive squares in 3 ways, for example, as 40119556 + 66725605969 = 6334^2 + 258313^2 .

It is not a de Polignac number, because 66765725525 - 2⁸ = 66765725269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66765725527) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1335314486 + ... + 1335314535.

It is an arithmetic number, because the mean of its divisors is an integer number (13798249947).

Almost surely, 2^66765725525 is an apocalyptic number.

It is an amenable number.

66765725525 is a deficient number, since it is larger than the sum of its proper divisors (16023774157).

66765725525 is a wasteful number, since it uses less digits than its factorization.

66765725525 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2670629031 (or 2670629026 counting only the distinct ones).

The product of its digits is 26460000, while the sum is 56.

The spelling of 66765725525 in words is "sixty-six billion, seven hundred sixty-five million, seven hundred twenty-five thousand, five hundred twenty-five".