1681971 has 8 divisors (see below), whose sum is σ = 2320080. Its totient is φ = 1082592.

The previous prime is 1681957. The next prime is 1681973. The reversal of 1681971 is 1791861.

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

It is not a de Polignac number, because 1681971 - 2⁶ = 1681907 is a prime.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (1681973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9580 + ... + 9753.

It is an arithmetic number, because the mean of its divisors is an integer number (290010).

2^1681971 is an apocalyptic number.

1681971 is a deficient number, since it is larger than the sum of its proper divisors (638109).

1681971 is a wasteful number, since it uses less digits than its factorization.

1681971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19365.

The product of its digits is 3024, while the sum is 33.

The square root of 1681971 is about 1296.9082465618. The cubic root of 1681971 is about 118.9249108472.

The spelling of 1681971 in words is "one million, six hundred eighty-one thousand, nine hundred seventy-one".