1680161 has 12 divisors (see below), whose sum is σ = 2070468. Its totient is φ = 1354752.

The previous prime is 1680149. The next prime is 1680167. The reversal of 1680161 is 1610861.

1680161 = T₁₃₄ + T₁₃₅ + ... + T₂₃₁.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1366561 + 313600 = 1169^2 + 560^2 .

It is not a de Polignac number, because 1680161 - 2¹⁴ = 1663777 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1680167) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 176 + ... + 1841.

It is an arithmetic number, because the mean of its divisors is an integer number (172539).

2^1680161 is an apocalyptic number.

It is an amenable number.

1680161 is a deficient number, since it is larger than the sum of its proper divisors (390307).

1680161 is a wasteful number, since it uses less digits than its factorization.

1680161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2048 (or 2041 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1680161 is about 1296.2102452920. The cubic root of 1680161 is about 118.8822364397.

It can be divided in two parts, 1680 and 161, that multiplied together give a triangular number (270480 = T₇₃₅).

The spelling of 1680161 in words is "one million, six hundred eighty thousand, one hundred sixty-one".