1681979 has 8 divisors (see below), whose sum is σ = 1829520. Its totient is φ = 1537056.

The previous prime is 1681973. The next prime is 1681991. The reversal of 1681979 is 9791861.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 1681979 - 2⁸ = 1681723 is a prime.

It is a Duffinian 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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 824 + ... + 2010.

It is an arithmetic number, because the mean of its divisors is an integer number (228690).

2^1681979 is an apocalyptic number.

1681979 is a deficient number, since it is larger than the sum of its proper divisors (147541).

1681979 is a wasteful number, since it uses less digits than its factorization.

1681979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1309.

The product of its digits is 27216, while the sum is 41.

The square root of 1681979 is about 1296.9113308164. The cubic root of 1681979 is about 118.9250993954.

The spelling of 1681979 in words is "one million, six hundred eighty-one thousand, nine hundred seventy-nine".