656209 has 4 divisors (see below), whose sum is σ = 661504. Its totient is φ = 650916.

The previous prime is 656171. The next prime is 656221. The reversal of 656209 is 902656.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 656209 - 2¹¹ = 654161 is a prime.

It is a super-2 number, since 2×656209² = 861220503362, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (656609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2457 + ... + 2710.

It is an arithmetic number, because the mean of its divisors is an integer number (165376).

2⁶⁵⁶²⁰⁹ is an apocalyptic number.

It is an amenable number.

656209 is a deficient number, since it is larger than the sum of its proper divisors (5295).

656209 is a wasteful number, since it uses less digits than its factorization.

656209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5294.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 656209 is about 810.0672811563. The cubic root of 656209 is about 86.8988563436.

The spelling of 656209 in words is "six hundred fifty-six thousand, two hundred nine".