213111161 has 2 divisors, whose sum is σ = 213111162. Its totient is φ = 213111160.

The previous prime is 213111149. The next prime is 213111181. The reversal of 213111161 is 161111312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 189888400 + 23222761 = 13780^2 + 4819^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-213111161 is a prime.

It is not a weakly prime, because it can be changed into another prime (213111131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106555580 + 106555581.

It is an arithmetic number, because the mean of its divisors is an integer number (106555581).

Almost surely, 2^213111161 is an apocalyptic number.

It is an amenable number.

213111161 is a deficient number, since it is larger than the sum of its proper divisors (1).

213111161 is an equidigital number, since it uses as much as digits as its factorization.

213111161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36, while the sum is 17.

The square root of 213111161 is about 14598.3273356916. The cubic root of 213111161 is about 597.3131349615.

Adding to 213111161 its reverse (161111312), we get a palindrome (374222473).

The spelling of 213111161 in words is "two hundred thirteen million, one hundred eleven thousand, one hundred sixty-one".