1679681 has 2 divisors, whose sum is σ = 1679682. Its totient is φ = 1679680.

The previous prime is 1679669. The next prime is 1679683. The reversal of 1679681 is 1869761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1343281 + 336400 = 1159^2 + 580^2 .

It is an emirp because it is prime and its reverse (1869761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1679681 - 2¹⁰ = 1678657 is a prime.

It is a super-2 number, since 2×1679681² = 5642656523522, which contains 22 as substring.

Together with 1679683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1679683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 839840 + 839841.

It is an arithmetic number, because the mean of its divisors is an integer number (839841).

2^1679681 is an apocalyptic number.

It is an amenable number.

1679681 is a deficient number, since it is larger than the sum of its proper divisors (1).

1679681 is an equidigital number, since it uses as much as digits as its factorization.

1679681 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18144, while the sum is 38.

The square root of 1679681 is about 1296.0250769179. The cubic root of 1679681 is about 118.8709143286.

It can be divided in two parts, 16 and 79681, that added together give a palindrome (79697).

The spelling of 1679681 in words is "one million, six hundred seventy-nine thousand, six hundred eighty-one".