1279281389 has 2 divisors, whose sum is σ = 1279281390. Its totient is φ = 1279281388.

The previous prime is 1279281383. The next prime is 1279281439. The reversal of 1279281389 is 9831829721.

It is an a-pointer prime, because the next prime (1279281439) can be obtained adding 1279281389 to its sum of digits (50).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1133668900 + 145612489 = 33670^2 + 12067^2 .

It is a cyclic number.

It is not a de Polignac number, because 1279281389 - 2¹⁶ = 1279215853 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1279281383) by changing a digit.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639640694 + 639640695.

It is an arithmetic number, because the mean of its divisors is an integer number (639640695).

Almost surely, 2^1279281389 is an apocalyptic number.

It is an amenable number.

1279281389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1279281389 is an equidigital number, since it uses as much as digits as its factorization.

1279281389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 50.

The square root of 1279281389 is about 35767.0433360098. The cubic root of 1279281389 is about 1085.5638200228.

The spelling of 1279281389 in words is "one billion, two hundred seventy-nine million, two hundred eighty-one thousand, three hundred eighty-nine".