2071681 has 2 divisors, whose sum is σ = 2071682. Its totient is φ = 2071680.

The previous prime is 2071669. The next prime is 2071687. The reversal of 2071681 is 1861702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1904400 + 167281 = 1380^2 + 409^2 .

It is a cyclic number.

It is not a de Polignac number, because 2071681 - 2⁵ = 2071649 is a prime.

It is a super-2 number, since 2×2071681² = 8583724331522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (2071687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1035840 + 1035841.

It is an arithmetic number, because the mean of its divisors is an integer number (1035841).

2^2071681 is an apocalyptic number.

It is an amenable number.

2071681 is a deficient number, since it is larger than the sum of its proper divisors (1).

2071681 is an equidigital number, since it uses as much as digits as its factorization.

2071681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 2071681 is about 1439.3335263239. Note that the first 3 decimals coincide. The cubic root of 2071681 is about 127.4796789349.

The spelling of 2071681 in words is "two million, seventy-one thousand, six hundred eighty-one".