1381643 has 2 divisors, whose sum is σ = 1381644. Its totient is φ = 1381642.

The previous prime is 1381637. The next prime is 1381649. The reversal of 1381643 is 3461831.

It is a balanced prime because it is at equal distance from previous prime (1381637) and next prime (1381649).

It is a cyclic number.

It is not a de Polignac number, because 1381643 - 2¹⁰ = 1380619 is a prime.

It is a Sophie Germain 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, 690821 + 690822.

It is an arithmetic number, because the mean of its divisors is an integer number (690822).

2^1381643 is an apocalyptic number.

1381643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1381643 is an equidigital number, since it uses as much as digits as its factorization.

1381643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 26.

The square root of 1381643 is about 1175.4331116657. The cubic root of 1381643 is about 111.3777944818.

The spelling of 1381643 in words is "one million, three hundred eighty-one thousand, six hundred forty-three".