660568961 has 4 divisors (see below), whose sum is σ = 711381972. Its totient is φ = 609755952.

The previous prime is 660568943. The next prime is 660568981. The reversal of 660568961 is 169865066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 102900736 + 557668225 = 10144^2 + 23615^2 .

It is not a de Polignac number, because 660568961 - 2¹⁰ = 660567937 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660568981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25406486 + ... + 25406511.

It is an arithmetic number, because the mean of its divisors is an integer number (177845493).

Almost surely, 2^660568961 is an apocalyptic number.

It is an amenable number.

660568961 is a deficient number, since it is larger than the sum of its proper divisors (50813011).

660568961 is a wasteful number, since it uses less digits than its factorization.

660568961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50813010.

The product of its (nonzero) digits is 466560, while the sum is 47.

The square root of 660568961 is about 25701.5361603154. The cubic root of 660568961 is about 870.9088845746.

The spelling of 660568961 in words is "six hundred sixty million, five hundred sixty-eight thousand, nine hundred sixty-one".