664146684 has 72 divisors (see below), whose sum is σ = 1781030160. Its totient is φ = 207954432.

The previous prime is 664146683. The next prime is 664146713. The reversal of 664146684 is 486641466.

664146684 = 2142² + 2143² + ... + 2277².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664146683) 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, 539782 + ... + 541010.

It is an arithmetic number, because the mean of its divisors is an integer number (24736530).

Almost surely, 2^664146684 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 664146684, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (890515080).

664146684 is an abundant number, since it is smaller than the sum of its proper divisors (1116883476).

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

664146684 is a wasteful number, since it uses less digits than its factorization.

664146684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2139 (or 2134 counting only the distinct ones).

The product of its digits is 663552, while the sum is 45.

The square root of 664146684 is about 25771.0435178710. The cubic root of 664146684 is about 872.4783711247.

The spelling of 664146684 in words is "six hundred sixty-four million, one hundred forty-six thousand, six hundred eighty-four".