1681398 has 40 divisors (see below), whose sum is σ = 3841992. Its totient is φ = 549504.

The previous prime is 1681397. The next prime is 1681403. The reversal of 1681398 is 8931861.

It is a d-powerful number, because it can be written as 1 + 6⁸ + 8³ + 1 + 3³ + 9³ + 8³ .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681397) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 15661 + ... + 15767.

2^1681398 is an apocalyptic number.

1681398 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1681398, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1920996).

1681398 is an abundant number, since it is smaller than the sum of its proper divisors (2160594).

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

1681398 is a wasteful number, since it uses less digits than its factorization.

1681398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 209 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 1681398 is about 1296.6873177447. The cubic root of 1681398 is about 118.9114045276.

The spelling of 1681398 in words is "one million, six hundred eighty-one thousand, three hundred ninety-eight".