66820285 has 16 divisors (see below), whose sum is σ = 97030656. Its totient is φ = 43123968.

The previous prime is 66820279. The next prime is 66820289. The reversal of 66820285 is 58202866.

It is not a de Polignac number, because 66820285 - 2³ = 66820277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66820289) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 55557 + ... + 56746.

It is an arithmetic number, because the mean of its divisors is an integer number (6064416).

Almost surely, 2^66820285 is an apocalyptic number.

It is an amenable number.

66820285 is a deficient number, since it is larger than the sum of its proper divisors (30210371).

66820285 is a wasteful number, since it uses less digits than its factorization.

66820285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 112332.

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 66820285 is about 8174.3675596342. The cubic root of 66820285 is about 405.7913400362.

The spelling of 66820285 in words is "sixty-six million, eight hundred twenty thousand, two hundred eighty-five".