123210161 has 2 divisors, whose sum is σ = 123210162. Its totient is φ = 123210160.

The previous prime is 123210133. The next prime is 123210163. The reversal of 123210161 is 161012321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71081761 + 52128400 = 8431^2 + 7220^2 .

It is a cyclic number.

It is not a de Polignac number, because 123210161 - 2¹⁸ = 122948017 is a prime.

It is a Sophie Germain prime.

Together with 123210163, it forms a pair of twin primes.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (123210163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61605080 + 61605081.

It is an arithmetic number, because the mean of its divisors is an integer number (61605081).

Almost surely, 2^123210161 is an apocalyptic number.

It is an amenable number.

123210161 is a deficient number, since it is larger than the sum of its proper divisors (1).

123210161 is an equidigital number, since it uses as much as digits as its factorization.

123210161 is an evil number, because the sum of its binary digits is even.

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

The square root of 123210161 is about 11100.0072522499. The cubic root of 123210161 is about 497.6020662115.

Adding to 123210161 its reverse (161012321), we get a palindrome (284222482).

The spelling of 123210161 in words is "one hundred twenty-three million, two hundred ten thousand, one hundred sixty-one".