66545525 has 6 divisors (see below), whose sum is σ = 82516482. Its totient is φ = 53236400.

The previous prime is 66545503. The next prime is 66545533. The reversal of 66545525 is 52554566.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 10804369 + 55741156 = 3287^2 + 7466^2 .

It is not a de Polignac number, because 66545525 - 2⁶ = 66545461 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1330886 + ... + 1330935.

It is an arithmetic number, because the mean of its divisors is an integer number (13752747).

Almost surely, 2^66545525 is an apocalyptic number.

It is an amenable number.

66545525 is a deficient number, since it is larger than the sum of its proper divisors (15970957).

66545525 is a wasteful number, since it uses less digits than its factorization.

66545525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2661831 (or 2661826 counting only the distinct ones).

The product of its digits is 180000, while the sum is 38.

The square root of 66545525 is about 8157.5440544321. The cubic root of 66545525 is about 405.2343814287.

The spelling of 66545525 in words is "sixty-six million, five hundred forty-five thousand, five hundred twenty-five".