655721280 has 336 divisors, whose sum is σ = 2439253440. Its totient is φ = 161071104.

The previous prime is 655721273. The next prime is 655721309. The reversal of 655721280 is 82127556.

It is a happy number.

655721280 is a `hidden beast` number, since 6 + 5 + 572 + 1 + 2 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2888527 + ... + 2888753.

Almost surely, 2^655721280 is an apocalyptic number.

655721280 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 655721280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1219626720).

655721280 is an abundant number, since it is smaller than the sum of its proper divisors (1783532160).

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

655721280 is a wasteful number, since it uses less digits than its factorization.

655721280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 326 (or 313 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 655721280 is about 25607.0552777940. The cubic root of 655721280 is about 868.7732214002.

The spelling of 655721280 in words is "six hundred fifty-five million, seven hundred twenty-one thousand, two hundred eighty".