1663424 has 56 divisors (see below), whose sum is σ = 3901440. Its totient is φ = 688896.

The previous prime is 1663397. The next prime is 1663457. The reversal of 1663424 is 4243661.

It is a tau number, because it is divible by the number of its divisors (56).

It is a d-powerful number, because it can be written as 1 + 6³ + 6⁴ + 3¹³ + 4 + 2¹¹ + 4⁸ .

It is a plaindrome in base 15.

It is a zygodrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 1663393 and 1663402.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21017 + ... + 21095.

2^1663424 is an apocalyptic number.

1663424 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1663424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1950720).

1663424 is an abundant number, since it is smaller than the sum of its proper divisors (2238016).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1663424 is an equidigital number, since it uses as much as digits as its factorization.

1663424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145 (or 135 counting only the distinct ones).

The product of its digits is 3456, while the sum is 26.

The square root of 1663424 is about 1289.7379578814. The cubic root of 1663424 is about 118.4861680996.

The spelling of 1663424 in words is "one million, six hundred sixty-three thousand, four hundred twenty-four".