213021161 has 2 divisors, whose sum is σ = 213021162. Its totient is φ = 213021160.

The previous prime is 213021157. The next prime is 213021191. The reversal of 213021161 is 161120312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 176491225 + 36529936 = 13285^2 + 6044^2 .

It is a cyclic number.

It is not a de Polignac number, because 213021161 - 2² = 213021157 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (213021191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106510580 + 106510581.

It is an arithmetic number, because the mean of its divisors is an integer number (106510581).

Almost surely, 2^213021161 is an apocalyptic number.

It is an amenable number.

213021161 is a deficient number, since it is larger than the sum of its proper divisors (1).

213021161 is an equidigital number, since it uses as much as digits as its factorization.

213021161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 213021161 is about 14595.2444652359. The cubic root of 213021161 is about 597.2290383938.

Adding to 213021161 its reverse (161120312), we get a palindrome (374141473).

The spelling of 213021161 in words is "two hundred thirteen million, twenty-one thousand, one hundred sixty-one".