64665217 has 8 divisors (see below), whose sum is σ = 65699424. Its totient is φ = 63637248.

The previous prime is 64665203. The next prime is 64665221. The reversal of 64665217 is 71256646.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 64665217 - 2⁷ = 64665089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64665257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22113 + ... + 24865.

It is an arithmetic number, because the mean of its divisors is an integer number (8212428).

Almost surely, 2^64665217 is an apocalyptic number.

It is an amenable number.

64665217 is a deficient number, since it is larger than the sum of its proper divisors (1034207).

64665217 is a wasteful number, since it uses less digits than its factorization.

64665217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3119.

The product of its digits is 60480, while the sum is 37.

The square root of 64665217 is about 8041.4685847798. The cubic root of 64665217 is about 401.3810947053.

It can be divided in two parts, 64 and 665217, that added together give a triangular number (665281 = T₁₁₅₃).

The spelling of 64665217 in words is "sixty-four million, six hundred sixty-five thousand, two hundred seventeen".