1261541387 has 2 divisors, whose sum is σ = 1261541388. Its totient is φ = 1261541386.

The previous prime is 1261541339. The next prime is 1261541399. The reversal of 1261541387 is 7831451621.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1261541387 - 2¹⁴ = 1261525003 is a prime.

It is a super-2 number, since 2×1261541387² = 3182973342227767538, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1261541387.

It is not a weakly prime, because it can be changed into another prime (1261541327) 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, 630770693 + 630770694.

It is an arithmetic number, because the mean of its divisors is an integer number (630770694).

Almost surely, 2^1261541387 is an apocalyptic number.

1261541387 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261541387 is an equidigital number, since it uses as much as digits as its factorization.

1261541387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40320, while the sum is 38.

The square root of 1261541387 is about 35518.1838921981. The cubic root of 1261541387 is about 1080.5225486261.

The spelling of 1261541387 in words is "one billion, two hundred sixty-one million, five hundred forty-one thousand, three hundred eighty-seven".