646965 has 24 divisors (see below), whose sum is σ = 1224288. Its totient is φ = 313440.

The previous prime is 646957. The next prime is 646979. The reversal of 646965 is 569646.

It is a happy number.

646965 is a `hidden beast` number, since 646 + 9 + 6 + 5 = 666.

It is not a de Polignac number, because 646965 - 2³ = 646957 is a prime.

It is a super-2 number, since 2×646965² = 837127422450, which contains 22 as substring.

It is a Curzon number.

It is a nialpdrome in base 15.

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 646965.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 159 + ... + 1148.

It is an arithmetic number, because the mean of its divisors is an integer number (51012).

2⁶⁴⁶⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

646965 is a deficient number, since it is larger than the sum of its proper divisors (577323).

646965 is a wasteful number, since it uses less digits than its factorization.

646965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1329 (or 1326 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 646965 is about 804.3413454498. The cubic root of 646965 is about 86.4888778064.

It can be divided in two parts, 6 and 46965, that added together give a triangular number (46971 = T₃₀₆).

The spelling of 646965 in words is "six hundred forty-six thousand, nine hundred sixty-five".