66477217 has 4 divisors (see below), whose sum is σ = 66496276. Its totient is φ = 66458160.

The previous prime is 66477209. The next prime is 66477221. The reversal of 66477217 is 71277466.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4004001 + 62473216 = 2001^2 + 7904^2 .

It is a cyclic number.

It is not a de Polignac number, because 66477217 - 2³ = 66477209 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66477217.

It is not an unprimeable number, because it can be changed into a prime (66477017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2634 + ... + 11827.

It is an arithmetic number, because the mean of its divisors is an integer number (16624069).

Almost surely, 2^66477217 is an apocalyptic number.

It is an amenable number.

66477217 is a deficient number, since it is larger than the sum of its proper divisors (19059).

66477217 is a wasteful number, since it uses less digits than its factorization.

66477217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19058.

The product of its digits is 98784, while the sum is 40.

The square root of 66477217 is about 8153.3561801261. The cubic root of 66477217 is about 405.0956782535.

The spelling of 66477217 in words is "sixty-six million, four hundred seventy-seven thousand, two hundred seventeen".