655957640 has 128 divisors (see below), whose sum is σ = 1636588800. Its totient is φ = 235146240.

The previous prime is 655957637. The next prime is 655957657. The reversal of 655957640 is 46759556.

It is a happy number.

655957640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 4024199 + ... + 4024361.

It is an arithmetic number, because the mean of its divisors is an integer number (12785850).

Almost surely, 2^655957640 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 655957640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (818294400).

655957640 is an abundant number, since it is smaller than the sum of its proper divisors (980631160).

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

655957640 is a wasteful number, since it uses less digits than its factorization.

655957640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 367 (or 363 counting only the distinct ones).

The product of its (nonzero) digits is 1134000, while the sum is 47.

The square root of 655957640 is about 25611.6699963122. The cubic root of 655957640 is about 868.8775942882.

The spelling of 655957640 in words is "six hundred fifty-five million, nine hundred fifty-seven thousand, six hundred forty".