1681988 has 48 divisors (see below), whose sum is σ = 3784704. Its totient is φ = 635040.

The previous prime is 1681973. The next prime is 1681991. The reversal of 1681988 is 8891861.

Its product of digits (27648) is a multiple of the sum of its prime factors (192).

It is a plaindrome in base 15.

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, 13181 + ... + 13307.

It is an arithmetic number, because the mean of its divisors is an integer number (78848).

2^1681988 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 1681988, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1892352).

1681988 is an abundant number, since it is smaller than the sum of its proper divisors (2102716).

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

1681988 is a wasteful number, since it uses less digits than its factorization.

1681988 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192 (or 190 counting only the distinct ones).

The product of its digits is 27648, while the sum is 41.

The square root of 1681988 is about 1296.9148005941. The cubic root of 1681988 is about 118.9253115114.

The spelling of 1681988 in words is "one million, six hundred eighty-one thousand, nine hundred eighty-eight".