655680 has 56 divisors (see below), whose sum is σ = 2084832. Its totient is φ = 174592.

The previous prime is 655657. The next prime is 655687. The reversal of 655680 is 86556.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655687) by changing a digit.

655680 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 619 + ... + 1301.

2⁶⁵⁵⁶⁸⁰ is an apocalyptic number.

655680 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 655680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1042416).

655680 is an abundant number, since it is smaller than the sum of its proper divisors (1429152).

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

655680 is a wasteful number, since it uses less digits than its factorization.

655680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 703 (or 693 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 30.

The square root of 655680 is about 809.7406992365. The cubic root of 655680 is about 86.8754990224.

The spelling of 655680 in words is "six hundred fifty-five thousand, six hundred eighty".