655561 has 2 divisors, whose sum is σ = 655562. Its totient is φ = 655560.

The previous prime is 655559. The next prime is 655579. The reversal of 655561 is 165556.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 435600 + 219961 = 660^2 + 469^2 .

It is a cyclic number.

It is not a de Polignac number, because 655561 - 2¹ = 655559 is a prime.

Together with 655559, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (655511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 327780 + 327781.

It is an arithmetic number, because the mean of its divisors is an integer number (327781).

2⁶⁵⁵⁵⁶¹ is an apocalyptic number.

It is an amenable number.

655561 is a deficient number, since it is larger than the sum of its proper divisors (1).

655561 is an equidigital number, since it uses as much as digits as its factorization.

655561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4500, while the sum is 28.

The square root of 655561 is about 809.6672155892. The cubic root of 655561 is about 86.8702429982.

The spelling of 655561 in words is "six hundred fifty-five thousand, five hundred sixty-one".