646845 has 16 divisors (see below), whose sum is σ = 1071360. Its totient is φ = 332864.

The previous prime is 646843. The next prime is 646859. The reversal of 646845 is 548646.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 646845 - 2¹ = 646843 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (646843) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 309 + ... + 1178.

It is an arithmetic number, because the mean of its divisors is an integer number (66960).

2⁶⁴⁶⁸⁴⁵ is an apocalyptic number.

It is an amenable number.

646845 is a deficient number, since it is larger than the sum of its proper divisors (424515).

646845 is a wasteful number, since it uses less digits than its factorization.

646845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1524.

The product of its digits is 23040, while the sum is 33.

The square root of 646845 is about 804.2667467949. The cubic root of 646845 is about 86.4835301152.

The spelling of 646845 in words is "six hundred forty-six thousand, eight hundred forty-five".