640720080 has 720 divisors, whose sum is σ = 2963810304. Its totient is φ = 121927680.

The previous prime is 640720037. The next prime is 640720103. The reversal of 640720080 is 80027046.

It is a tau number, because it is divible by the number of its divisors (720).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 5044977 + ... + 5045103.

Almost surely, 2^640720080 is an apocalyptic number.

640720080 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 640720080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1481905152).

640720080 is an abundant number, since it is smaller than the sum of its proper divisors (2323090224).

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

640720080 is a wasteful number, since it uses less digits than its factorization.

640720080 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 640720080 is about 25312.4491110600. The cubic root of 640720080 is about 862.0969559853.

The spelling of 640720080 in words is "six hundred forty million, seven hundred twenty thousand, eighty".