646540 has 12 divisors (see below), whose sum is σ = 1357776. Its totient is φ = 258608.

The previous prime is 646537. The next prime is 646543. The reversal of 646540 is 45646.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (646537) and next prime (646543).

It is not an unprimeable number, because it can be changed into a prime (646543) 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 3 ways as a sum of consecutive naturals, for example, 16144 + ... + 16183.

It is an arithmetic number, because the mean of its divisors is an integer number (113148).

2⁶⁴⁶⁵⁴⁰ is an apocalyptic number.

It is an amenable number.

646540 is an abundant number, since it is smaller than the sum of its proper divisors (711236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

646540 is a wasteful number, since it uses less digits than its factorization.

646540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32336 (or 32334 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 646540 is about 804.0771107301. The cubic root of 646540 is about 86.4699350893.

The spelling of 646540 in words is "six hundred forty-six thousand, five hundred forty".