1663680 has 56 divisors (see below), whose sum is σ = 5285232. Its totient is φ = 443392.

The previous prime is 1663619. The next prime is 1663681. The reversal of 1663680 is 863661.

It is a super-2 number, since 2×1663680² = 5535662284800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (1663681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94 + ... + 1826.

2^1663680 is an apocalyptic number.

1663680 is a gapful number since it is divisible by the number (10) 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 1663680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2642616).

1663680 is an abundant number, since it is smaller than the sum of its proper divisors (3621552).

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

1663680 is a wasteful number, since it uses less digits than its factorization.

1663680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1753 (or 1743 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 1663680 is about 1289.8371990294. The cubic root of 1663680 is about 118.4922461055.

The spelling of 1663680 in words is "one million, six hundred sixty-three thousand, six hundred eighty".