1663943 has 4 divisors (see below), whose sum is σ = 1761840. Its totient is φ = 1566048.

The previous prime is 1663919. The next prime is 1663951. The reversal of 1663943 is 3493661.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1663943 - 2⁸ = 1663687 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663913) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48923 + ... + 48956.

It is an arithmetic number, because the mean of its divisors is an integer number (440460).

2^1663943 is an apocalyptic number.

1663943 is a deficient number, since it is larger than the sum of its proper divisors (97897).

1663943 is an equidigital number, since it uses as much as digits as its factorization.

1663943 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97896.

The product of its digits is 11664, while the sum is 32.

The square root of 1663943 is about 1289.9391458515. The cubic root of 1663943 is about 118.4984896577.

The spelling of 1663943 in words is "one million, six hundred sixty-three thousand, nine hundred forty-three".