1281382889 has 2 divisors, whose sum is σ = 1281382890. Its totient is φ = 1281382888.

The previous prime is 1281382873. The next prime is 1281382891. The reversal of 1281382889 is 9882831821.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 954315664 + 327067225 = 30892^2 + 18085^2 .

It is an emirp because it is prime and its reverse (9882831821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1281382889 - 2⁴ = 1281382873 is a prime.

Together with 1281382891, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1281382849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640691444 + 640691445.

It is an arithmetic number, because the mean of its divisors is an integer number (640691445).

Almost surely, 2^1281382889 is an apocalyptic number.

It is an amenable number.

1281382889 is a deficient number, since it is larger than the sum of its proper divisors (1).

1281382889 is an equidigital number, since it uses as much as digits as its factorization.

1281382889 is an evil number, because the sum of its binary digits is even.

The product of its digits is 442368, while the sum is 50.

The square root of 1281382889 is about 35796.4088841325. The cubic root of 1281382889 is about 1086.1579203099.

The spelling of 1281382889 in words is "one billion, two hundred eighty-one million, three hundred eighty-two thousand, eight hundred eighty-nine".