705661 has 4 divisors (see below), whose sum is σ = 769824. Its totient is φ = 641500.

The previous prime is 705643. The next prime is 705689. The reversal of 705661 is 166507.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166507 = 11 ⋅15137.

It is a cyclic number.

It is not a de Polignac number, because 705661 - 2⁷ = 705533 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (705631) 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 in 3 ways as a sum of consecutive naturals, for example, 32065 + ... + 32086.

It is an arithmetic number, because the mean of its divisors is an integer number (192456).

2⁷⁰⁵⁶⁶¹ is an apocalyptic number.

It is an amenable number.

705661 is a deficient number, since it is larger than the sum of its proper divisors (64163).

705661 is a wasteful number, since it uses less digits than its factorization.

705661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64162.

The product of its (nonzero) digits is 1260, while the sum is 25.

The square root of 705661 is about 840.0363087391. The cubic root of 705661 is about 89.0291113790.

It can be divided in two parts, 7056 and 61, that added together give a palindrome (7117).

The spelling of 705661 in words is "seven hundred five thousand, six hundred sixty-one".