1638743 has 2 divisors, whose sum is σ = 1638744. Its totient is φ = 1638742.

The previous prime is 1638733. The next prime is 1638797. The reversal of 1638743 is 3478361.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1638743 - 2⁸ = 1638487 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1638733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 819371 + 819372.

It is an arithmetic number, because the mean of its divisors is an integer number (819372).

2^1638743 is an apocalyptic number.

1638743 is a deficient number, since it is larger than the sum of its proper divisors (1).

1638743 is an equidigital number, since it uses as much as digits as its factorization.

1638743 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 32.

The square root of 1638743 is about 1280.1339773633. The cubic root of 1638743 is about 117.8972340934.

The spelling of 1638743 in words is "one million, six hundred thirty-eight thousand, seven hundred forty-three".