640158720 has 176 divisors, whose sum is σ = 2079883008. Its totient is φ = 168017920.

The previous prime is 640158703. The next prime is 640158721. The reversal of 640158720 is 27851046.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640158721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1090267 + ... + 1090853.

Almost surely, 2^640158720 is an apocalyptic number.

640158720 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 640158720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1039941504).

640158720 is an abundant number, since it is smaller than the sum of its proper divisors (1439724288).

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

640158720 is a wasteful number, since it uses less digits than its factorization.

640158720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 640158720 is about 25301.3580663173. The cubic root of 640158720 is about 861.8451100981.

The spelling of 640158720 in words is "six hundred forty million, one hundred fifty-eight thousand, seven hundred twenty".