1663872 has 64 divisors (see below), whose sum is σ = 5059200. Its totient is φ = 474624.

The previous prime is 1663867. The next prime is 1663873. The reversal of 1663872 is 2783661.

It is a tau number, because it is divible by the number of its divisors (64).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663873) 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, 2379 + ... + 2997.

It is an arithmetic number, because the mean of its divisors is an integer number (79050).

2^1663872 is an apocalyptic number.

1663872 is a gapful number since it is divisible by the number (12) 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 1663872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2529600).

1663872 is an abundant number, since it is smaller than the sum of its proper divisors (3395328).

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

1663872 is an equidigital number, since it uses as much as digits as its factorization.

1663872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643 (or 631 counting only the distinct ones).

The product of its digits is 12096, while the sum is 33.

The square root of 1663872 is about 1289.9116248798. The cubic root of 1663872 is about 118.4968042009.

The spelling of 1663872 in words is "one million, six hundred sixty-three thousand, eight hundred seventy-two".