1681939 has 8 divisors (see below), whose sum is σ = 1932128. Its totient is φ = 1434240.

The previous prime is 1681931. The next prime is 1681957. The reversal of 1681939 is 9391861.

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 1681939 - 2³ = 1681931 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1681898 and 1681907.

It is not an unprimeable number, because it can be changed into a prime (1681931) 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, 1189 + ... + 2185.

It is an arithmetic number, because the mean of its divisors is an integer number (241516).

2^1681939 is an apocalyptic number.

1681939 is a deficient number, since it is larger than the sum of its proper divisors (250189).

1681939 is an equidigital number, since it uses as much as digits as its factorization.

1681939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1245.

The product of its digits is 11664, while the sum is 37.

The square root of 1681939 is about 1296.8959094700. The cubic root of 1681939 is about 118.9241566484.

The spelling of 1681939 in words is "one million, six hundred eighty-one thousand, nine hundred thirty-nine".