1261544057 has 2 divisors, whose sum is σ = 1261544058. Its totient is φ = 1261544056.

The previous prime is 1261544027. The next prime is 1261544149. The reversal of 1261544057 is 7504451621.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1244396176 + 17147881 = 35276^2 + 4141^2 .

It is a cyclic number.

It is not a de Polignac number, because 1261544057 - 2¹⁰ = 1261543033 is a prime.

It is not a weakly prime, because it can be changed into another prime (1261544027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 630772028 + 630772029.

It is an arithmetic number, because the mean of its divisors is an integer number (630772029).

Almost surely, 2^1261544057 is an apocalyptic number.

It is an amenable number.

1261544057 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261544057 is an equidigital number, since it uses as much as digits as its factorization.

1261544057 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 33600, while the sum is 35.

The square root of 1261544057 is about 35518.2214785594. The cubic root of 1261544057 is about 1080.5233109193.

Adding to 1261544057 its reverse (7504451621), we get a palindrome (8765995678).

The spelling of 1261544057 in words is "one billion, two hundred sixty-one million, five hundred forty-four thousand, fifty-seven".