66828725 has 6 divisors (see below), whose sum is σ = 82867650. Its totient is φ = 53462960.

The previous prime is 66828709. The next prime is 66828739. The reversal of 66828725 is 52782866.

It can be written as a sum of positive squares in 3 ways, for example, as 15319396 + 51509329 = 3914^2 + 7177^2 .

It is not a de Polignac number, because 66828725 - 2⁴ = 66828709 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1336550 + ... + 1336599.

It is an arithmetic number, because the mean of its divisors is an integer number (13811275).

Almost surely, 2^66828725 is an apocalyptic number.

It is an amenable number.

66828725 is a deficient number, since it is larger than the sum of its proper divisors (16038925).

66828725 is a wasteful number, since it uses less digits than its factorization.

66828725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2673159 (or 2673154 counting only the distinct ones).

The product of its digits is 322560, while the sum is 44.

The square root of 66828725 is about 8174.8837912230. The cubic root of 66828725 is about 405.8084243428.

The spelling of 66828725 in words is "sixty-six million, eight hundred twenty-eight thousand, seven hundred twenty-five".