660864764 has 72 divisors (see below), whose sum is σ = 1449423360. Its totient is φ = 262017504.

The previous prime is 660864719. The next prime is 660864767. The reversal of 660864764 is 467468066.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660864767) 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, 158069 + ... + 162195.

It is an arithmetic number, because the mean of its divisors is an integer number (20130880).

Almost surely, 2^660864764 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 660864764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (724711680).

660864764 is an abundant number, since it is smaller than the sum of its proper divisors (788558596).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

660864764 is a wasteful number, since it uses less digits than its factorization.

660864764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4207 (or 4198 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 47.

The square root of 660864764 is about 25707.2900944460. The cubic root of 660864764 is about 871.0388629376.

The spelling of 660864764 in words is "six hundred sixty million, eight hundred sixty-four thousand, seven hundred sixty-four".