646975 has 12 divisors (see below), whose sum is σ = 917104. Its totient is φ = 443520.

The previous prime is 646957. The next prime is 646979. The reversal of 646975 is 579646.

It is a de Polignac number, because none of the positive numbers 2^k-646975 is a prime.

It is a hoax number, since the sum of its digits (37) coincides with the sum of the digits of its distinct prime factors.

It is a d-powerful number, because it can be written as 6⁷ + 4² + 9⁴ + 6⁷ + 7⁴ + 5⁷ .

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646979) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1674 + ... + 2023.

2⁶⁴⁶⁹⁷⁵ is an apocalyptic number.

646975 is a deficient number, since it is larger than the sum of its proper divisors (270129).

646975 is a wasteful number, since it uses less digits than its factorization.

646975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3714 (or 3709 counting only the distinct ones).

The product of its digits is 45360, while the sum is 37.

The square root of 646975 is about 804.3475616921. The cubic root of 646975 is about 86.4893234175.

The spelling of 646975 in words is "six hundred forty-six thousand, nine hundred seventy-five".