1681864 has 8 divisors (see below), whose sum is σ = 3153510. Its totient is φ = 840928.

The previous prime is 1681853. The next prime is 1681871. The reversal of 1681864 is 4681861.

It can be written as a sum of positive squares in only one way, i.e., 1119364 + 562500 = 1058^2 + 750^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105109 + ... + 105124.

2^1681864 is an apocalyptic number.

It is an amenable number.

1681864 is a deficient number, since it is larger than the sum of its proper divisors (1471646).

1681864 is a wasteful number, since it uses less digits than its factorization.

1681864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210239 (or 210235 counting only the distinct ones).

The product of its digits is 9216, while the sum is 34.

The square root of 1681864 is about 1296.8669939512. The cubic root of 1681864 is about 118.9223889576.

The spelling of 1681864 in words is "one million, six hundred eighty-one thousand, eight hundred sixty-four".