1381609 has 2 divisors, whose sum is σ = 1381610. Its totient is φ = 1381608.

The previous prime is 1381559. The next prime is 1381613. The reversal of 1381609 is 9061831.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1243225 + 138384 = 1115^2 + 372^2 .

It is a cyclic number.

It is not a de Polignac number, because 1381609 - 2¹³ = 1373417 is a prime.

It is not a weakly prime, because it can be changed into another prime (1381649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 690804 + 690805.

It is an arithmetic number, because the mean of its divisors is an integer number (690805).

2^1381609 is an apocalyptic number.

It is an amenable number.

1381609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381609 is an equidigital number, since it uses as much as digits as its factorization.

1381609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 28.

The square root of 1381609 is about 1175.4186488226. The cubic root of 1381609 is about 111.3768808652.

The spelling of 1381609 in words is "one million, three hundred eighty-one thousand, six hundred nine".