66544417 has 4 divisors (see below), whose sum is σ = 66602416. Its totient is φ = 66486420.

The previous prime is 66544397. The next prime is 66544459. The reversal of 66544417 is 71444566.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66544417 - 2¹⁵ = 66511649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66544487) 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, 27243 + ... + 29584.

It is an arithmetic number, because the mean of its divisors is an integer number (16650604).

Almost surely, 2^66544417 is an apocalyptic number.

It is an amenable number.

66544417 is a deficient number, since it is larger than the sum of its proper divisors (57999).

66544417 is a wasteful number, since it uses less digits than its factorization.

66544417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57998.

The product of its digits is 80640, while the sum is 37.

The square root of 66544417 is about 8157.4761415526. The cubic root of 66544417 is about 405.2321323309.

The spelling of 66544417 in words is "sixty-six million, five hundred forty-four thousand, four hundred seventeen".