123121261 has 2 divisors, whose sum is σ = 123121262. Its totient is φ = 123121260.

The previous prime is 123121253. The next prime is 123121301. The reversal of 123121261 is 162121321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122877225 + 244036 = 11085^2 + 494^2 .

It is a cyclic number.

It is not a de Polignac number, because 123121261 - 2³ = 123121253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (123121961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61560630 + 61560631.

It is an arithmetic number, because the mean of its divisors is an integer number (61560631).

Almost surely, 2^123121261 is an apocalyptic number.

It is an amenable number.

123121261 is a deficient number, since it is larger than the sum of its proper divisors (1).

123121261 is an equidigital number, since it uses as much as digits as its factorization.

123121261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 19.

The square root of 123121261 is about 11096.0020277576. The cubic root of 123121261 is about 497.4823589108.

Adding to 123121261 its reverse (162121321), we get a palindrome (285242582).

The spelling of 123121261 in words is "one hundred twenty-three million, one hundred twenty-one thousand, two hundred sixty-one".