660961 has 16 divisors (see below), whose sum is σ = 806400. Its totient is φ = 540960.

The previous prime is 660949. The next prime is 660973. The reversal of 660961 is 169066.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (660949) and next prime (660973).

It is not a de Polignac number, because 660961 - 2⁷ = 660833 is a prime.

It is a nialpdrome in base 7.

It is not an unprimeable number, because it can be changed into a prime (660901) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14040 + ... + 14086.

It is an arithmetic number, because the mean of its divisors is an integer number (50400).

2⁶⁶⁰⁹⁶¹ is an apocalyptic number.

It is an amenable number.

660961 is a deficient number, since it is larger than the sum of its proper divisors (145439).

660961 is an equidigital number, since it uses as much as digits as its factorization.

660961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 660961 is about 812.9950799359. The cubic root of 660961 is about 87.1081141495.

It can be divided in two parts, 6609 and 61, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 660961 in words is "six hundred sixty thousand, nine hundred sixty-one".