66538425 has 48 divisors (see below), whose sum is σ = 121599360. Its totient is φ = 31933440.

The previous prime is 66538421. The next prime is 66538481. The reversal of 66538425 is 52483566.

It is not a de Polignac number, because 66538425 - 2² = 66538421 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66538421) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 28191 + ... + 30459.

It is an arithmetic number, because the mean of its divisors is an integer number (2533320).

Almost surely, 2^66538425 is an apocalyptic number.

It is an amenable number.

66538425 is a deficient number, since it is larger than the sum of its proper divisors (55060935).

66538425 is a wasteful number, since it uses less digits than its factorization.

66538425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2322 (or 2317 counting only the distinct ones).

The product of its digits is 172800, while the sum is 39.

The square root of 66538425 is about 8157.1088628263. The cubic root of 66538425 is about 405.2199689071.

The spelling of 66538425 in words is "sixty-six million, five hundred thirty-eight thousand, four hundred twenty-five".