656643 has 16 divisors (see below), whose sum is σ = 957600. Its totient is φ = 397824.

The previous prime is 656609. The next prime is 656651. The reversal of 656643 is 346656.

656643 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 656643 - 2¹⁴ = 640259 is a prime.

656643 is strictly pandigital in base 7.

It is a self number, because there is not a number n which added to its sum of digits gives 656643.

It is not an unprimeable number, because it can be changed into a prime (656603) 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, 4333 + ... + 4481.

It is an arithmetic number, because the mean of its divisors is an integer number (59850).

2⁶⁵⁶⁶⁴³ is an apocalyptic number.

656643 is a deficient number, since it is larger than the sum of its proper divisors (300957).

656643 is a wasteful number, since it uses less digits than its factorization.

656643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278.

The product of its digits is 12960, while the sum is 30.

The square root of 656643 is about 810.3351158626. The cubic root of 656643 is about 86.9180096887.

The spelling of 656643 in words is "six hundred fifty-six thousand, six hundred forty-three".