1684381 has 4 divisors (see below), whose sum is σ = 1687392. Its totient is φ = 1681372.

The previous prime is 1684379. The next prime is 1684387. The reversal of 1684381 is 1834861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1684381 - 2¹ = 1684379 is a prime.

It is a super-2 number, since 2×1684381² = 5674278706322, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1684387) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 391 + ... + 1876.

It is an arithmetic number, because the mean of its divisors is an integer number (421848).

2^1684381 is an apocalyptic number.

It is an amenable number.

1684381 is a deficient number, since it is larger than the sum of its proper divisors (3011).

1684381 is an equidigital number, since it uses as much as digits as its factorization.

1684381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3010.

The product of its digits is 4608, while the sum is 31.

The square root of 1684381 is about 1297.8370467821. The cubic root of 1684381 is about 118.9816839734.

The spelling of 1684381 in words is "one million, six hundred eighty-four thousand, three hundred eighty-one".