213141661 has 2 divisors, whose sum is σ = 213141662. Its totient is φ = 213141660.

The previous prime is 213141659. The next prime is 213141671. The reversal of 213141661 is 166141312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201100761 + 12040900 = 14181^2 + 3470^2 .

It is a cyclic number.

It is not a de Polignac number, because 213141661 - 2¹ = 213141659 is a prime.

Together with 213141659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (213141671) 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, 106570830 + 106570831.

It is an arithmetic number, because the mean of its divisors is an integer number (106570831).

Almost surely, 2^213141661 is an apocalyptic number.

It is an amenable number.

213141661 is a deficient number, since it is larger than the sum of its proper divisors (1).

213141661 is an equidigital number, since it uses as much as digits as its factorization.

213141661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 213141661 is about 14599.3719385458. The cubic root of 213141661 is about 597.3416289823.

Adding to 213141661 its reverse (166141312), we get a palindrome (379282973).

The spelling of 213141661 in words is "two hundred thirteen million, one hundred forty-one thousand, six hundred sixty-one".