653561 has 2 divisors, whose sum is σ = 653562. Its totient is φ = 653560.

The previous prime is 653539. The next prime is 653563. The reversal of 653561 is 165356.

653561 is nontrivially palindromic in base 16.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 383161 + 270400 = 619^2 + 520^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-653561 is a prime.

It is a Sophie Germain prime.

Together with 653563, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 653561.

It is not a weakly prime, because it can be changed into another prime (653563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 326780 + 326781.

It is an arithmetic number, because the mean of its divisors is an integer number (326781).

2⁶⁵³⁵⁶¹ is an apocalyptic number.

It is an amenable number.

653561 is a deficient number, since it is larger than the sum of its proper divisors (1).

653561 is an equidigital number, since it uses as much as digits as its factorization.

653561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 26.

The square root of 653561 is about 808.4311968251. The cubic root of 653561 is about 86.7818111208.

The spelling of 653561 in words is "six hundred fifty-three thousand, five hundred sixty-one".