655537680 has 360 divisors, whose sum is σ = 2714069592. Its totient is φ = 140894208.

The previous prime is 655537661. The next prime is 655537681. The reversal of 655537680 is 86735556.

655537680 is a `hidden beast` number, since 6 + 55 + 537 + 68 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 338412816 + 317124864 = 18396^2 + 17808^2 .

It is a tau number, because it is divible by the number of its divisors (360).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655537681) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 599214 + ... + 600306.

Almost surely, 2^655537680 is an apocalyptic number.

655537680 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 655537680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1357034796).

655537680 is an abundant number, since it is smaller than the sum of its proper divisors (2058531912).

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

655537680 is a wasteful number, since it uses less digits than its factorization.

655537680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1143 (or 1127 counting only the distinct ones).

The product of its (nonzero) digits is 756000, while the sum is 45.

The square root of 655537680 is about 25603.4700773157. The cubic root of 655537680 is about 868.6921291955.

The spelling of 655537680 in words is "six hundred fifty-five million, five hundred thirty-seven thousand, six hundred eighty".