1261530287 has 2 divisors, whose sum is σ = 1261530288. Its totient is φ = 1261530286.

The previous prime is 1261530253. The next prime is 1261530293. The reversal of 1261530287 is 7820351621.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (7820351621) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1261530287 - 2¹⁶ = 1261464751 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261530227) 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, 630765143 + 630765144.

It is an arithmetic number, because the mean of its divisors is an integer number (630765144).

Almost surely, 2^1261530287 is an apocalyptic number.

1261530287 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261530287 is an equidigital number, since it uses as much as digits as its factorization.

1261530287 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 1261530287 is about 35518.0276338650. The cubic root of 1261530287 is about 1080.5193795306.

The spelling of 1261530287 in words is "one billion, two hundred sixty-one million, five hundred thirty thousand, two hundred eighty-seven".