123256321 has 2 divisors, whose sum is σ = 123256322. Its totient is φ = 123256320.

The previous prime is 123256277. The next prime is 123256327. The reversal of 123256321 is 123652321.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 73342096 + 49914225 = 8564^2 + 7065^2 .

It is a cyclic number.

It is not a de Polignac number, because 123256321 - 2¹³ = 123248129 is a prime.

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

It is not a weakly prime, because it can be changed into another prime (123256327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 61628160 + 61628161.

It is an arithmetic number, because the mean of its divisors is an integer number (61628161).

Almost surely, 2^123256321 is an apocalyptic number.

It is an amenable number.

123256321 is a deficient number, since it is larger than the sum of its proper divisors (1).

123256321 is an equidigital number, since it uses as much as digits as its factorization.

123256321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2160, while the sum is 25.

The square root of 123256321 is about 11102.0863354597. The cubic root of 123256321 is about 497.6641997329.

The spelling of 123256321 in words is "one hundred twenty-three million, two hundred fifty-six thousand, three hundred twenty-one".