1306123261 has 2 divisors, whose sum is σ = 1306123262. Its totient is φ = 1306123260.

The previous prime is 1306123249. The next prime is 1306123307. The reversal of 1306123261 is 1623216031.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 745617636 + 560505625 = 27306^2 + 23675^2 .

It is a cyclic number.

It is not a de Polignac number, because 1306123261 - 2²³ = 1297734653 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1306123201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 653061630 + 653061631.

It is an arithmetic number, because the mean of its divisors is an integer number (653061631).

Almost surely, 2^1306123261 is an apocalyptic number.

It is an amenable number.

1306123261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1306123261 is an equidigital number, since it uses as much as digits as its factorization.

1306123261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 1306123261 is about 36140.3273504820. The cubic root of 1306123261 is about 1093.1037595414.

Adding to 1306123261 its reverse (1623216031), we get a palindrome (2929339292).

The spelling of 1306123261 in words is "one billion, three hundred six million, one hundred twenty-three thousand, two hundred sixty-one".