1663945 has 8 divisors (see below), whose sum is σ = 2026944. Its totient is φ = 1311024.

The previous prime is 1663919. The next prime is 1663951. The reversal of 1663945 is 5493661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1663945 - 2⁵ = 1663913 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1663945.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2149 + ... + 2818.

It is an arithmetic number, because the mean of its divisors is an integer number (253368).

2^1663945 is an apocalyptic number.

It is an amenable number.

1663945 is a deficient number, since it is larger than the sum of its proper divisors (362999).

1663945 is an equidigital number, since it uses as much as digits as its factorization.

1663945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5039.

The product of its digits is 19440, while the sum is 34.

The square root of 1663945 is about 1289.9399210816. The cubic root of 1663945 is about 118.4985371347.

The spelling of 1663945 in words is "one million, six hundred sixty-three thousand, nine hundred forty-five".