1656609 has 16 divisors (see below), whose sum is σ = 2334720. Its totient is φ = 1043280.

The previous prime is 1656607. The next prime is 1656617. The reversal of 1656609 is 9066561.

1656609 = T₄₂₀ + T₄₂₁ + ... + T₄₃₇.

It is not a de Polignac number, because 1656609 - 2¹ = 1656607 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1656609.

It is not an unprimeable number, because it can be changed into a prime (1656607) 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, 4182 + ... + 4560.

It is an arithmetic number, because the mean of its divisors is an integer number (145920).

2^1656609 is an apocalyptic number.

It is an amenable number.

1656609 is a deficient number, since it is larger than the sum of its proper divisors (678111).

1656609 is a wasteful number, since it uses less digits than its factorization.

1656609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 460.

The product of its (nonzero) digits is 9720, while the sum is 33.

The square root of 1656609 is about 1287.0932367160. The cubic root of 1656609 is about 118.3241351487.

The spelling of 1656609 in words is "one million, six hundred fifty-six thousand, six hundred nine".