1681994 has 8 divisors (see below), whose sum is σ = 2655840. Its totient is φ = 796716.

The previous prime is 1681991. The next prime is 1682017. The reversal of 1681994 is 4991861.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Harshad number since it is a multiple of its sum of digits (38), and also a Moran number because the ratio is a prime number: 44263 = 1681994 / (1 + 6 + 8 + 1 + 9 + 9 + 4).

It is an Ulam number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1681991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22094 + ... + 22169.

It is an arithmetic number, because the mean of its divisors is an integer number (331980).

2^1681994 is an apocalyptic number.

1681994 is a deficient number, since it is larger than the sum of its proper divisors (973846).

1681994 is a wasteful number, since it uses less digits than its factorization.

1681994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44284.

The product of its digits is 15552, while the sum is 38.

The square root of 1681994 is about 1296.9171137740. The cubic root of 1681994 is about 118.9254529216.

The spelling of 1681994 in words is "one million, six hundred eighty-one thousand, nine hundred ninety-four".