646517 has 4 divisors (see below), whose sum is σ = 648480. Its totient is φ = 644556.

The previous prime is 646453. The next prime is 646519. The reversal of 646517 is 715646.

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: 715646 = 2 ⋅357823.

It is a cyclic number.

It is not a de Polignac number, because 646517 - 2⁶ = 646453 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 646517.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646517.

It is not an unprimeable number, because it can be changed into a prime (646519) 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 3 ways as a sum of consecutive naturals, for example, 353 + ... + 1190.

It is an arithmetic number, because the mean of its divisors is an integer number (162120).

2⁶⁴⁶⁵¹⁷ is an apocalyptic number.

It is an amenable number.

646517 is a deficient number, since it is larger than the sum of its proper divisors (1963).

646517 is a wasteful number, since it uses less digits than its factorization.

646517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1962.

The product of its digits is 5040, while the sum is 29.

The square root of 646517 is about 804.0628084920. The cubic root of 646517 is about 86.4689097173.

The spelling of 646517 in words is "six hundred forty-six thousand, five hundred seventeen".