1681408 has 24 divisors (see below), whose sum is σ = 3366090. Its totient is φ = 839680.

The previous prime is 1681403. The next prime is 1681411. The reversal of 1681408 is 8041861.

It can be written as a sum of positive squares in only one way, i.e., 1557504 + 123904 = 1248^2 + 352^2 .

It is not an unprimeable number, because it can be changed into a prime (1681403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1638 + ... + 2458.

2^1681408 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 1681408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1683045).

1681408 is an abundant number, since it is smaller than the sum of its proper divisors (1684682).

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

1681408 is an frugal number, since it uses more digits than its factorization.

1681408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 843 (or 823 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 1681408 is about 1296.6911737187. The cubic root of 1681408 is about 118.9116402663.

The spelling of 1681408 in words is "one million, six hundred eighty-one thousand, four hundred eight".