609561 has 12 divisors (see below), whose sum is σ = 891540. Its totient is φ = 401280.

The previous prime is 609541. The next prime is 609571. The reversal of 609561 is 165906.

609561 is a `hidden beast` number, since 609 + 56 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 38025 + 571536 = 195^2 + 756^2 .

It is a de Polignac number, because none of the positive numbers 2^k-609561 is a prime.

It is a super-2 number, since 2×609561² = 743129225442, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (609541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 421 + ... + 1181.

It is an arithmetic number, because the mean of its divisors is an integer number (74295).

2⁶⁰⁹⁵⁶¹ is an apocalyptic number.

It is an amenable number.

609561 is a deficient number, since it is larger than the sum of its proper divisors (281979).

609561 is a wasteful number, since it uses less digits than its factorization.

609561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 856 (or 853 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 609561 is about 780.7438760567. The cubic root of 609561 is about 84.7889110485.

The spelling of 609561 in words is "six hundred nine thousand, five hundred sixty-one".