66994225 has 9 divisors (see below), whose sum is σ = 83123617. Its totient is φ = 53562640.

The previous prime is 66994219. The next prime is 66994231. The reversal of 66994225 is 52249966.

The square root of 66994225 is 8185.

It is a perfect power (a square), and thus also a powerful number.

66994225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (66994219) and next prime (66994231).

It can be written as a sum of positive squares in 4 ways, for example, as 31281649 + 35712576 = 5593^2 + 5976^2 .

It is not a de Polignac number, because 66994225 - 2¹⁹ = 66469937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 40107 + ... + 41743.

Almost surely, 2^66994225 is an apocalyptic number.

66994225 is the 8185-th square number.

66994225 is the 4093-rd centered octagonal number.

It is an amenable number.

66994225 is a deficient number, since it is larger than the sum of its proper divisors (16129392).

66994225 is an frugal number, since it uses more digits than its factorization.

66994225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3284 (or 1642 counting only the distinct ones).

The product of its digits is 233280, while the sum is 43.

The cubic root of 66994225 is about 406.1431403360.

The spelling of 66994225 in words is "sixty-six million, nine hundred ninety-four thousand, two hundred twenty-five".