660664287 has 24 divisors (see below), whose sum is σ = 976275456. Its totient is φ = 430402896.

The previous prime is 660664253. The next prime is 660664327. The reversal of 660664287 is 782466066.

It is not a de Polignac number, because 660664287 - 2⁸ = 660664031 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660664237) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 72268 + ... + 80894.

It is an arithmetic number, because the mean of its divisors is an integer number (40678144).

Almost surely, 2^660664287 is an apocalyptic number.

660664287 is a gapful number since it is divisible by the number (67) formed by its first and last digit.

660664287 is a deficient number, since it is larger than the sum of its proper divisors (315611169).

660664287 is a wasteful number, since it uses less digits than its factorization.

660664287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8827 (or 8824 counting only the distinct ones).

The product of its (nonzero) digits is 580608, while the sum is 45.

The square root of 660664287 is about 25703.3905740079. The cubic root of 660664287 is about 870.9507758693.

The spelling of 660664287 in words is "six hundred sixty million, six hundred sixty-four thousand, two hundred eighty-seven".