657985680 has 480 divisors, whose sum is σ = 2661579648. Its totient is φ = 149299200.

The previous prime is 657985673. The next prime is 657985717. The reversal of 657985680 is 86589756.

657985680 is a `hidden beast` number, since 6 + 5 + 79 + 8 + 568 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 3635190 + ... + 3635370.

Almost surely, 2^657985680 is an apocalyptic number.

657985680 is a gapful number since it is divisible by the number (60) 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 657985680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1330789824).

657985680 is an abundant number, since it is smaller than the sum of its proper divisors (2003593968).

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

657985680 is a wasteful number, since it uses less digits than its factorization.

657985680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237 (or 219 counting only the distinct ones).

The product of its (nonzero) digits is 3628800, while the sum is 54.

The square root of 657985680 is about 25651.2315493818. The cubic root of 657985680 is about 869.7721162954.

The spelling of 657985680 in words is "six hundred fifty-seven million, nine hundred eighty-five thousand, six hundred eighty".