655720000 has 210 divisors, whose sum is σ = 1778819658. Its totient is φ = 239616000.

The previous prime is 655719947. The next prime is 655720019. The reversal of 655720000 is 27556.

It is a happy number.

It can be written as a sum of positive squares in 15 ways, for example, as 595750464 + 59969536 = 24408^2 + 7744^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 6759952 + ... + 6760048.

Almost surely, 2^655720000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 655720000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (889409829).

655720000 is an abundant number, since it is smaller than the sum of its proper divisors (1123099658).

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

655720000 is an equidigital number, since it uses as much as digits as its factorization.

655720000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 655720000 is about 25607.0302846699. The cubic root of 655720000 is about 868.7726561039.

Adding to 655720000 its reverse (27556), we get a palindrome (655747556).

The spelling of 655720000 in words is "six hundred fifty-five million, seven hundred twenty thousand".