646645517 has 8 divisors (see below), whose sum is σ = 739182912. Its totient is φ = 554148000.

The previous prime is 646645499. The next prime is 646645561. The reversal of 646645517 is 715546646.

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

It is not a de Polignac number, because 646645517 - 2²⁸ = 378210061 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646645217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 45017 + ... + 57617.

It is an arithmetic number, because the mean of its divisors is an integer number (92397864).

Almost surely, 2^646645517 is an apocalyptic number.

It is an amenable number.

646645517 is a deficient number, since it is larger than the sum of its proper divisors (92537395).

646645517 is a wasteful number, since it uses less digits than its factorization.

646645517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19939.

The product of its digits is 604800, while the sum is 44.

The square root of 646645517 is about 25429.2256468812. The cubic root of 646645517 is about 864.7463887241.

The spelling of 646645517 in words is "six hundred forty-six million, six hundred forty-five thousand, five hundred seventeen".