646955 has 8 divisors (see below), whose sum is σ = 793152. Its totient is φ = 506368.

The previous prime is 646937. The next prime is 646957. The reversal of 646955 is 559646.

It is a happy number.

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-646955 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 7 and base 15.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 646955.

It is not an unprimeable number, because it can be changed into a prime (646957) 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, 1142 + ... + 1611.

It is an arithmetic number, because the mean of its divisors is an integer number (99144).

2⁶⁴⁶⁹⁵⁵ is an apocalyptic number.

646955 is a deficient number, since it is larger than the sum of its proper divisors (146197).

646955 is a wasteful number, since it uses less digits than its factorization.

646955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2805.

The product of its digits is 32400, while the sum is 35.

The square root of 646955 is about 804.3351291595. The cubic root of 646955 is about 86.4884321907.

The spelling of 646955 in words is "six hundred forty-six thousand, nine hundred fifty-five".