66817265 has 16 divisors (see below), whose sum is σ = 82639056. Its totient is φ = 51840000.

The previous prime is 66817253. The next prime is 66817273. The reversal of 66817265 is 56271866.

It can be written as a sum of positive squares in 8 ways, for example, as 6615184 + 60202081 = 2572^2 + 7759^2 .

It is not a de Polignac number, because 66817265 - 2¹⁰ = 66816241 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 (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20765 + ... + 23765.

It is an arithmetic number, because the mean of its divisors is an integer number (5164941).

Almost surely, 2^66817265 is an apocalyptic number.

It is an amenable number.

66817265 is a deficient number, since it is larger than the sum of its proper divisors (15821791).

66817265 is a wasteful number, since it uses less digits than its factorization.

66817265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3140.

The product of its digits is 120960, while the sum is 41.

The square root of 66817265 is about 8174.1828337761. The cubic root of 66817265 is about 405.7852265817.

The spelling of 66817265 in words is "sixty-six million, eight hundred seventeen thousand, two hundred sixty-five".