1281067261 has 2 divisors, whose sum is σ = 1281067262. Its totient is φ = 1281067260.

The previous prime is 1281067253. The next prime is 1281067273. The reversal of 1281067261 is 1627601821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1009015225 + 272052036 = 31765^2 + 16494^2 .

It is an emirp because it is prime and its reverse (1627601821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1281067261 - 2³ = 1281067253 is a prime.

It is a super-2 number, since 2×1281067261² = 3282266654412084242, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1281067201) 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, 640533630 + 640533631.

It is an arithmetic number, because the mean of its divisors is an integer number (640533631).

Almost surely, 2^1281067261 is an apocalyptic number.

It is an amenable number.

1281067261 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281067261 is an equidigital number, since it uses as much as digits as its factorization.

1281067261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 1281067261 is about 35791.9999580912. Note that the first 4 decimals coincide. The cubic root of 1281067261 is about 1086.0687328113.

The spelling of 1281067261 in words is "one billion, two hundred eighty-one million, sixty-seven thousand, two hundred sixty-one".