705681 has 12 divisors (see below), whose sum is σ = 1031940. Its totient is φ = 464640.

The previous prime is 705643. The next prime is 705689. The reversal of 705681 is 186507.

705681 = T₂₁₅ + T₂₁₆ + ... + T₂₄₁.

It can be written as a sum of positive squares in 2 ways, for example, as 129600 + 576081 = 360^2 + 759^2 .

It is not a de Polignac number, because 705681 - 2⁹ = 705169 is a prime.

It is a super-2 number, since 2×705681² = 995971347522, which contains 22 as substring.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 705681.

It is not an unprimeable number, because it can be changed into a prime (705689) 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, 361 + ... + 1241.

It is an arithmetic number, because the mean of its divisors is an integer number (85995).

2⁷⁰⁵⁶⁸¹ is an apocalyptic number.

It is an amenable number.

705681 is a deficient number, since it is larger than the sum of its proper divisors (326259).

705681 is a wasteful number, since it uses less digits than its factorization.

705681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 705681 is about 840.0482129021. The cubic root of 705681 is about 89.0299524653.

It can be divided in two parts, 7056 and 81, that multiplied together give a square (571536 = 756²).

The spelling of 705681 in words is "seven hundred five thousand, six hundred eighty-one".