646697 has 8 divisors (see below), whose sum is σ = 693000. Its totient is φ = 601344.

The previous prime is 646687. The next prime is 646721. The reversal of 646697 is 796646.

It can be written as a sum of positive squares in 4 ways, for example, as 309136 + 337561 = 556^2 + 581^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-646697 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 646697.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646697.

It is not an unprimeable number, because it can be changed into a prime (646637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1679 + ... + 2027.

It is an arithmetic number, because the mean of its divisors is an integer number (86625).

2⁶⁴⁶⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

646697 is a deficient number, since it is larger than the sum of its proper divisors (46303).

646697 is a wasteful number, since it uses less digits than its factorization.

646697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 475.

The product of its digits is 54432, while the sum is 38.

The square root of 646697 is about 804.1747322566. The cubic root of 646697 is about 86.4769337184.

The spelling of 646697 in words is "six hundred forty-six thousand, six hundred ninety-seven".