1261004321 has 2 divisors, whose sum is σ = 1261004322. Its totient is φ = 1261004320.

The previous prime is 1261004299. The next prime is 1261004341. The reversal of 1261004321 is 1234001621.

It is an a-pointer prime, because the next prime (1261004341) can be obtained adding 1261004321 to its sum of digits (20).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1246866721 + 14137600 = 35311^2 + 3760^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261004321 - 2¹⁰ = 1261003297 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1261004293 and 1261004302.

It is not a weakly prime, because it can be changed into another prime (1261004341) 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, 630502160 + 630502161.

It is an arithmetic number, because the mean of its divisors is an integer number (630502161).

Almost surely, 2^1261004321 is an apocalyptic number.

It is an amenable number.

1261004321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261004321 is an equidigital number, since it uses as much as digits as its factorization.

1261004321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 1261004321 is about 35510.6226501310. The cubic root of 1261004321 is about 1080.3691927661.

Adding to 1261004321 its reverse (1234001621), we get a palindrome (2495005942).

The spelling of 1261004321 in words is "one billion, two hundred sixty-one million, four thousand, three hundred twenty-one".