1289239397 has 2 divisors, whose sum is σ = 1289239398. Its totient is φ = 1289239396.

The previous prime is 1289239379. The next prime is 1289239429. The reversal of 1289239397 is 7939329821.

It is a happy number.

Together with previous prime (1289239379) 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., 866772481 + 422466916 = 29441^2 + 20554^2 .

It is an emirp because it is prime and its reverse (7939329821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1289239397 - 2¹² = 1289235301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1289239097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644619698 + 644619699.

It is an arithmetic number, because the mean of its divisors is an integer number (644619699).

Almost surely, 2^1289239397 is an apocalyptic number.

It is an amenable number.

1289239397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1289239397 is an equidigital number, since it uses as much as digits as its factorization.

1289239397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1469664, while the sum is 53.

The square root of 1289239397 is about 35905.9799615607. The cubic root of 1289239397 is about 1088.3732423679.

The spelling of 1289239397 in words is "one billion, two hundred eighty-nine million, two hundred thirty-nine thousand, three hundred ninety-seven".