655686720 has 336 divisors, whose sum is σ = 2469684672. Its totient is φ = 158699520.

The previous prime is 655686697. The next prime is 655686721. The reversal of 655686720 is 27686556.

655686720 is a `hidden beast` number, since 6 + 5 + 568 + 67 + 20 = 666.

It is a super-3 number, since 3×655686720³ (a number of 27 digits) contains 333 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (655686721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3107415 + ... + 3107625.

It is an arithmetic number, because the mean of its divisors is an integer number (7350252).

Almost surely, 2^655686720 is an apocalyptic number.

655686720 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 655686720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1234842336).

655686720 is an abundant number, since it is smaller than the sum of its proper divisors (1813997952).

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

655686720 is a wasteful number, since it uses less digits than its factorization.

655686720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 317 counting only the distinct ones).

The product of its (nonzero) digits is 604800, while the sum is 45.

The square root of 655686720 is about 25606.3804548788. The cubic root of 655686720 is about 868.7579581418.

The spelling of 655686720 in words is "six hundred fifty-five million, six hundred eighty-six thousand, seven hundred twenty".