66351617 has 4 divisors (see below), whose sum is σ = 66370560. Its totient is φ = 66332676.

The previous prime is 66351569. The next prime is 66351683. The reversal of 66351617 is 71615366.

It is a happy number.

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, and also an emirpimes, since its reverse is a distinct semiprime: 71615366 = 2 ⋅35807683.

It is a cyclic number.

It is not a de Polignac number, because 66351617 - 2⁸ = 66351361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66351317) 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, 2513 + ... + 11790.

It is an arithmetic number, because the mean of its divisors is an integer number (16592640).

Almost surely, 2^66351617 is an apocalyptic number.

It is an amenable number.

66351617 is a deficient number, since it is larger than the sum of its proper divisors (18943).

66351617 is a wasteful number, since it uses less digits than its factorization.

66351617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18942.

The product of its digits is 22680, while the sum is 35.

The square root of 66351617 is about 8145.6501889045. The cubic root of 66351617 is about 404.8403923232.

The spelling of 66351617 in words is "sixty-six million, three hundred fifty-one thousand, six hundred seventeen".