1381409 has 2 divisors, whose sum is σ = 1381410. Its totient is φ = 1381408.

The previous prime is 1381397. The next prime is 1381411. The reversal of 1381409 is 9041831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1380625 + 784 = 1175^2 + 28^2 .

It is a cyclic number.

It is not a de Polignac number, because 1381409 - 2⁸ = 1381153 is a prime.

It is a Sophie Germain prime.

Together with 1381411, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1381439) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690704 + 690705.

It is an arithmetic number, because the mean of its divisors is an integer number (690705).

2^1381409 is an apocalyptic number.

It is an amenable number.

1381409 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381409 is an equidigital number, since it uses as much as digits as its factorization.

1381409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 1381409 is about 1175.3335696729. Note that the first 3 decimals coincide. The cubic root of 1381409 is about 111.3715063462.

The spelling of 1381409 in words is "one million, three hundred eighty-one thousand, four hundred nine".