1680361 has 2 divisors, whose sum is σ = 1680362. Its totient is φ = 1680360.

The previous prime is 1680359. The next prime is 1680373. The reversal of 1680361 is 1630861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1265625 + 414736 = 1125^2 + 644^2 .

It is a cyclic number.

It is not a de Polignac number, because 1680361 - 2¹ = 1680359 is a prime.

It is a super-2 number, since 2×1680361² = 5647226180642, which contains 22 as substring.

Together with 1680359, it forms a pair of twin primes.

It is a d-powerful number, because it can be written as 1 + 6 + 8 + 0 + 3⁶ + 6⁸ + 1 .

It is not a weakly prime, because it can be changed into another prime (1680461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 840180 + 840181.

It is an arithmetic number, because the mean of its divisors is an integer number (840181).

2^1680361 is an apocalyptic number.

It is an amenable number.

1680361 is a deficient number, since it is larger than the sum of its proper divisors (1).

1680361 is an equidigital number, since it uses as much as digits as its factorization.

1680361 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1680361 is about 1296.2873909747. The cubic root of 1680361 is about 118.8869533495.

The spelling of 1680361 in words is "one million, six hundred eighty thousand, three hundred sixty-one".