66315625 has 12 divisors (see below), whose sum is σ = 82893132. Its totient is φ = 53050000.

The previous prime is 66315619. The next prime is 66315629. The reversal of 66315625 is 52651366.

It can be written as a sum of positive squares in 6 ways, for example, as 37015056 + 29300569 = 6084^2 + 5413^2 .

It is not a de Polignac number, because 66315625 - 2¹⁵ = 66282857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66315629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7486 + ... + 13735.

It is an arithmetic number, because the mean of its divisors is an integer number (6907761).

Almost surely, 2^66315625 is an apocalyptic number.

It is an amenable number.

66315625 is a deficient number, since it is larger than the sum of its proper divisors (16577507).

66315625 is an frugal number, since it uses more digits than its factorization.

66315625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21246 (or 21226 counting only the distinct ones).

The product of its digits is 32400, while the sum is 34.

The square root of 66315625 is about 8143.4406119281. The cubic root of 66315625 is about 404.7671780771.

The spelling of 66315625 in words is "sixty-six million, three hundred fifteen thousand, six hundred twenty-five".