1663944 has 64 divisors (see below), whose sum is σ = 4536000. Its totient is φ = 506880.

The previous prime is 1663919. The next prime is 1663951. The reversal of 1663944 is 4493661.

1663944 is nontrivially palindromic in base 7.

It is a super-3 number, since 3×1663944³ = 13820933355380209152, which contains 333 as substring.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18652 + ... + 18740.

It is an arithmetic number, because the mean of its divisors is an integer number (70875).

2^1663944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1663944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2268000).

1663944 is an abundant number, since it is smaller than the sum of its proper divisors (2872056).

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

1663944 is a wasteful number, since it uses less digits than its factorization.

1663944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158 (or 154 counting only the distinct ones).

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

The square root of 1663944 is about 1289.9395334666. The cubic root of 1663944 is about 118.4985133962.

The spelling of 1663944 in words is "one million, six hundred sixty-three thousand, nine hundred forty-four".