1381437509 has 2 divisors, whose sum is σ = 1381437510. Its totient is φ = 1381437508.

The previous prime is 1381437457. The next prime is 1381437511. The reversal of 1381437509 is 9057341831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1120776484 + 260661025 = 33478^2 + 16145^2 .

It is a cyclic number.

It is not a de Polignac number, because 1381437509 - 2²⁴ = 1364660293 is a prime.

Together with 1381437511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1381437599) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690718754 + 690718755.

It is an arithmetic number, because the mean of its divisors is an integer number (690718755).

Almost surely, 2^1381437509 is an apocalyptic number.

It is an amenable number.

1381437509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381437509 is an equidigital number, since it uses as much as digits as its factorization.

1381437509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 41.

The square root of 1381437509 is about 37167.6944267465. The cubic root of 1381437509 is about 1113.7227248875.

The spelling of 1381437509 in words is "one billion, three hundred eighty-one million, four hundred thirty-seven thousand, five hundred nine".