657705664 has 112 divisors (see below), whose sum is σ = 1642116096. Its totient is φ = 256016640.

The previous prime is 657705661. The next prime is 657705667. The reversal of 657705664 is 466507756.

It is an interprime number because it is at equal distance from previous prime (657705661) and next prime (657705667).

It is a tau number, because it is divible by the number of its divisors (112).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (657705661) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 595737 + ... + 596839.

Almost surely, 2^657705664 is an apocalyptic number.

657705664 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 657705664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (821058048).

657705664 is an abundant number, since it is smaller than the sum of its proper divisors (984410432).

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

657705664 is a wasteful number, since it uses less digits than its factorization.

657705664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155 (or 1123 counting only the distinct ones).

The product of its (nonzero) digits is 1058400, while the sum is 46.

The square root of 657705664 is about 25645.7728290648. The cubic root of 657705664 is about 869.6487171226.

The spelling of 657705664 in words is "six hundred fifty-seven million, seven hundred five thousand, six hundred sixty-four".