66217025 has 24 divisors (see below), whose sum is σ = 95392704. Its totient is φ = 44654400.

The previous prime is 66216929. The next prime is 66217027. The reversal of 66217025 is 52071266.

It is not a de Polignac number, because 66217025 - 2¹⁸ = 65954881 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 (66217027) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7574 + ... + 13776.

It is an arithmetic number, because the mean of its divisors is an integer number (3974696).

Almost surely, 2^66217025 is an apocalyptic number.

It is an amenable number.

66217025 is a deficient number, since it is larger than the sum of its proper divisors (29175679).

66217025 is a wasteful number, since it uses less digits than its factorization.

66217025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6281 (or 6276 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 66217025 is about 8137.3844077812. The cubic root of 66217025 is about 404.5664720347.

The spelling of 66217025 in words is "sixty-six million, two hundred seventeen thousand, twenty-five".