640097760 has 48 divisors (see below), whose sum is σ = 2016309456. Its totient is φ = 170692608.

The previous prime is 640097749. The next prime is 640097761. The reversal of 640097760 is 67790046.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640097761) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 666289 + ... + 667248.

It is an arithmetic number, because the mean of its divisors is an integer number (42006447).

Almost surely, 2^640097760 is an apocalyptic number.

640097760 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640097760 is an abundant number, since it is smaller than the sum of its proper divisors (1376211696).

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

640097760 is a wasteful number, since it uses less digits than its factorization.

640097760 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1333555 (or 1333547 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 39.

The square root of 640097760 is about 25300.1533592190. The cubic root of 640097760 is about 861.8177524320.

The spelling of 640097760 in words is "six hundred forty million, ninety-seven thousand, seven hundred sixty".