1681944 has 64 divisors (see below), whose sum is σ = 4803840. Its totient is φ = 485760.

The previous prime is 1681931. The next prime is 1681957. The reversal of 1681944 is 4491861.

It is an interprime number because it is at equal distance from previous prime (1681931) and next prime (1681957).

It is a super-3 number, since 3×1681944³ = 14274333872976241152, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

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, 5934 + ... + 6210.

It is an arithmetic number, because the mean of its divisors is an integer number (75060).

2^1681944 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 1681944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2401920).

1681944 is an abundant number, since it is smaller than the sum of its proper divisors (3121896).

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

1681944 is a wasteful number, since it uses less digits than its factorization.

1681944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 320 (or 316 counting only the distinct ones).

The product of its digits is 6912, while the sum is 33.

The square root of 1681944 is about 1296.8978371483. The cubic root of 1681944 is about 118.9242744926.

It can be divided in two parts, 168 and 1944, that added together give a palindrome (2112).

The spelling of 1681944 in words is "one million, six hundred eighty-one thousand, nine hundred forty-four".