210561361 has 2 divisors, whose sum is σ = 210561362. Its totient is φ = 210561360.

The previous prime is 210561359. The next prime is 210561443. The reversal of 210561361 is 163165012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 208513600 + 2047761 = 14440^2 + 1431^2 .

It is a cyclic number.

It is not a de Polignac number, because 210561361 - 2¹ = 210561359 is a prime.

Together with 210561359, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (210561161) 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, 105280680 + 105280681.

It is an arithmetic number, because the mean of its divisors is an integer number (105280681).

Almost surely, 2^210561361 is an apocalyptic number.

It is an amenable number.

210561361 is a deficient number, since it is larger than the sum of its proper divisors (1).

210561361 is an equidigital number, since it uses as much as digits as its factorization.

210561361 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 210561361 is about 14510.7326141722. The cubic root of 210561361 is about 594.9213567410.

The spelling of 210561361 in words is "two hundred ten million, five hundred sixty-one thousand, three hundred sixty-one".