1261948609 has 2 divisors, whose sum is σ = 1261948610. Its totient is φ = 1261948608.

The previous prime is 1261948577. The next prime is 1261948643. The reversal of 1261948609 is 9068491621.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1079779600 + 182169009 = 32860^2 + 13497^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261948609 - 2⁵ = 1261948577 is a prime.

It is not a weakly prime, because it can be changed into another prime (1261948679) 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, 630974304 + 630974305.

It is an arithmetic number, because the mean of its divisors is an integer number (630974305).

Almost surely, 2^1261948609 is an apocalyptic number.

It is an amenable number.

1261948609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261948609 is an equidigital number, since it uses as much as digits as its factorization.

1261948609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 1261948609 is about 35523.9160144261. The cubic root of 1261948609 is about 1080.6387993284.

The spelling of 1261948609 in words is "one billion, two hundred sixty-one million, nine hundred forty-eight thousand, six hundred nine".