66858225 has 48 divisors (see below), whose sum is σ = 127039488. Its totient is φ = 30392640.

The previous prime is 66858221. The next prime is 66858247. The reversal of 66858225 is 52285866.

It is not a de Polignac number, because 66858225 - 2² = 66858221 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66858221) 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, 181992 + ... + 182358.

It is an arithmetic number, because the mean of its divisors is an integer number (2646656).

Almost surely, 2^66858225 is an apocalyptic number.

It is an amenable number.

66858225 is a deficient number, since it is larger than the sum of its proper divisors (60181263).

66858225 is a wasteful number, since it uses less digits than its factorization.

66858225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 734 (or 729 counting only the distinct ones).

The product of its digits is 230400, while the sum is 42.

The square root of 66858225 is about 8176.6878991435. The cubic root of 66858225 is about 405.8681271501.

The spelling of 66858225 in words is "sixty-six million, eight hundred fifty-eight thousand, two hundred twenty-five".