1281761497 has 2 divisors, whose sum is σ = 1281761498. Its totient is φ = 1281761496.

The previous prime is 1281761479. The next prime is 1281761539. The reversal of 1281761497 is 7941671821.

It is a happy number.

Together with previous prime (1281761479) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1228923136 + 52838361 = 35056^2 + 7269^2 .

It is an emirp because it is prime and its reverse (7941671821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1281761497 - 2²⁷ = 1147543769 is a prime.

It is not a weakly prime, because it can be changed into another prime (1281761417) 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, 640880748 + 640880749.

It is an arithmetic number, because the mean of its divisors is an integer number (640880749).

Almost surely, 2^1281761497 is an apocalyptic number.

It is an amenable number.

1281761497 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281761497 is an equidigital number, since it uses as much as digits as its factorization.

1281761497 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 169344, while the sum is 46.

The square root of 1281761497 is about 35801.6968452614. The cubic root of 1281761497 is about 1086.2648848470.

The spelling of 1281761497 in words is "one billion, two hundred eighty-one million, seven hundred sixty-one thousand, four hundred ninety-seven".