1663447 has 4 divisors (see below), whose sum is σ = 1672920. Its totient is φ = 1653976.

The previous prime is 1663397. The next prime is 1663457. The reversal of 1663447 is 7443661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7443661 = 1429 ⋅5209.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1663447 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 (1663457) 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, 4468 + ... + 4825.

It is an arithmetic number, because the mean of its divisors is an integer number (418230).

2^1663447 is an apocalyptic number.

1663447 is a deficient number, since it is larger than the sum of its proper divisors (9473).

1663447 is an equidigital number, since it uses as much as digits as its factorization.

1663447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9472.

The product of its digits is 12096, while the sum is 31.

The square root of 1663447 is about 1289.7468743905. The cubic root of 1663447 is about 118.4867141959.

The spelling of 1663447 in words is "one million, six hundred sixty-three thousand, four hundred forty-seven".