1338257509 has 2 divisors, whose sum is σ = 1338257510. Its totient is φ = 1338257508.

The previous prime is 1338257497. The next prime is 1338257563. The reversal of 1338257509 is 9057528331.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 734572609 + 603684900 = 27103^2 + 24570^2 .

It is a cyclic number.

It is not a de Polignac number, because 1338257509 - 2¹⁷ = 1338126437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1338257009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 669128754 + 669128755.

It is an arithmetic number, because the mean of its divisors is an integer number (669128755).

Almost surely, 2^1338257509 is an apocalyptic number.

It is an amenable number.

1338257509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1338257509 is an equidigital number, since it uses as much as digits as its factorization.

1338257509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 226800, while the sum is 43.

The square root of 1338257509 is about 36582.2020796999. The cubic root of 1338257509 is about 1101.9956908735.

The spelling of 1338257509 in words is "one billion, three hundred thirty-eight million, two hundred fifty-seven thousand, five hundred nine".