213610561 has 2 divisors, whose sum is σ = 213610562. Its totient is φ = 213610560.

The previous prime is 213610469. The next prime is 213610577. The reversal of 213610561 is 165016312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179024400 + 34586161 = 13380^2 + 5881^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213610561 is a prime.

It is not a weakly prime, because it can be changed into another prime (213610961) 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, 106805280 + 106805281.

It is an arithmetic number, because the mean of its divisors is an integer number (106805281).

Almost surely, 2^213610561 is an apocalyptic number.

It is an amenable number.

213610561 is a deficient number, since it is larger than the sum of its proper divisors (1).

213610561 is an equidigital number, since it uses as much as digits as its factorization.

213610561 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 213610561 is about 14615.4220260655. The cubic root of 213610561 is about 597.7793477940.

Adding to 213610561 its reverse (165016312), we get a palindrome (378626873).

The spelling of 213610561 in words is "two hundred thirteen million, six hundred ten thousand, five hundred sixty-one".