1663638 has 8 divisors (see below), whose sum is σ = 3327288. Its totient is φ = 554544.

The previous prime is 1663619. The next prime is 1663681. The reversal of 1663638 is 8363661.

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

1663638 is an admirable number.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 1663599 and 1663608.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 138631 + ... + 138642.

It is an arithmetic number, because the mean of its divisors is an integer number (415911).

2^1663638 is an apocalyptic number.

1663638 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

1663638 is a wasteful number, since it uses less digits than its factorization.

1663638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 277278.

The product of its digits is 15552, while the sum is 33.

The square root of 1663638 is about 1289.8209178022. The cubic root of 1663638 is about 118.4912489754.

The spelling of 1663638 in words is "one million, six hundred sixty-three thousand, six hundred thirty-eight".