660971 has 4 divisors (see below), whose sum is σ = 663432. Its totient is φ = 658512.

The previous prime is 660949. The next prime is 660973. The reversal of 660971 is 179066.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 179066 = 2 ⋅89533.

It is a cyclic number.

It is not a de Polignac number, because 660971 - 2¹⁰ = 659947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (660973) 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, 770 + ... + 1383.

It is an arithmetic number, because the mean of its divisors is an integer number (165858).

2⁶⁶⁰⁹⁷¹ is an apocalyptic number.

660971 is a deficient number, since it is larger than the sum of its proper divisors (2461).

660971 is a wasteful number, since it uses less digits than its factorization.

660971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2460.

The product of its (nonzero) digits is 2268, while the sum is 29.

The square root of 660971 is about 813.0012300114. The cubic root of 660971 is about 87.1085534476.

The spelling of 660971 in words is "six hundred sixty thousand, nine hundred seventy-one".