123121321409 has 2 divisors, whose sum is σ = 123121321410. Its totient is φ = 123121321408.

The previous prime is 123121321391. The next prime is 123121321439. The reversal of 123121321409 is 904123121321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 121973467009 + 1147854400 = 349247^2 + 33880^2 .

It is a cyclic number.

It is not a de Polignac number, because 123121321409 - 2²⁰ = 123120272833 is a prime.

It is not a weakly prime, because it can be changed into another prime (123121321439) 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, 61560660704 + 61560660705.

It is an arithmetic number, because the mean of its divisors is an integer number (61560660705).

Almost surely, 2^123121321409 is an apocalyptic number.

It is an amenable number.

123121321409 is a deficient number, since it is larger than the sum of its proper divisors (1).

123121321409 is an equidigital number, since it uses as much as digits as its factorization.

123121321409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 29.

The spelling of 123121321409 in words is "one hundred twenty-three billion, one hundred twenty-one million, three hundred twenty-one thousand, four hundred nine".