1663409 has 16 divisors (see below), whose sum is σ = 1922496. Its totient is φ = 1425600.

The previous prime is 1663397. The next prime is 1663457. The reversal of 1663409 is 9043661.

1663409 is nontrivially palindromic in base 5.

It is not a de Polignac number, because 1663409 - 2¹⁶ = 1597873 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (1663009) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24794 + ... + 24860.

It is an arithmetic number, because the mean of its divisors is an integer number (120156).

2^1663409 is an apocalyptic number.

It is an amenable number.

1663409 is a deficient number, since it is larger than the sum of its proper divisors (259087).

1663409 is a wasteful number, since it uses less digits than its factorization.

1663409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176.

The product of its (nonzero) digits is 3888, while the sum is 29.

The square root of 1663409 is about 1289.7321427335. The cubic root of 1663409 is about 118.4858119471.

The spelling of 1663409 in words is "one million, six hundred sixty-three thousand, four hundred nine".