1663897 has 4 divisors (see below), whose sum is σ = 1691236. Its totient is φ = 1636560.

The previous prime is 1663891. The next prime is 1663913. The reversal of 1663897 is 7983661.

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

It can be written as a sum of positive squares in 2 ways, for example, as 173056 + 1490841 = 416^2 + 1221^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1663897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1663891) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 13578 + ... + 13699.

It is an arithmetic number, because the mean of its divisors is an integer number (422809).

2^1663897 is an apocalyptic number.

It is an amenable number.

1663897 is a deficient number, since it is larger than the sum of its proper divisors (27339).

1663897 is an equidigital number, since it uses as much as digits as its factorization.

1663897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27338.

The product of its digits is 54432, while the sum is 40.

The square root of 1663897 is about 1289.9213154297. The cubic root of 1663897 is about 118.4973976771.

The spelling of 1663897 in words is "one million, six hundred sixty-three thousand, eight hundred ninety-seven".