1285681289 has 2 divisors, whose sum is σ = 1285681290. Its totient is φ = 1285681288.

The previous prime is 1285681279. The next prime is 1285681333. The reversal of 1285681289 is 9821865821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 940464889 + 345216400 = 30667^2 + 18580^2 .

It is a cyclic number.

It is not a de Polignac number, because 1285681289 - 2¹² = 1285677193 is a prime.

It is not a weakly prime, because it can be changed into another prime (1285681279) 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, 642840644 + 642840645.

It is an arithmetic number, because the mean of its divisors is an integer number (642840645).

Almost surely, 2^1285681289 is an apocalyptic number.

It is an amenable number.

1285681289 is a deficient number, since it is larger than the sum of its proper divisors (1).

1285681289 is an equidigital number, since it uses as much as digits as its factorization.

1285681289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 552960, while the sum is 50.

The square root of 1285681289 is about 35856.3981598821. The cubic root of 1285681289 is about 1087.3710707064.

The spelling of 1285681289 in words is "one billion, two hundred eighty-five million, six hundred eighty-one thousand, two hundred eighty-nine".