640268544 has 72 divisors (see below), whose sum is σ = 1759082752. Its totient is φ = 206530560.

The previous prime is 640268543. The next prime is 640268647. The reversal of 640268544 is 445862046.

It is not an unprimeable number, because it can be changed into a prime (640268543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10362 + ... + 37254.

Almost surely, 2^640268544 is an apocalyptic number.

640268544 is a gapful number since it is divisible by the number (64) 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 640268544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (879541376).

640268544 is an abundant number, since it is smaller than the sum of its proper divisors (1118814208).

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

640268544 is a wasteful number, since it uses less digits than its factorization.

640268544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26943 (or 26929 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 39.

The square root of 640268544 is about 25303.5282915249. The cubic root of 640268544 is about 861.8943925975.

The spelling of 640268544 in words is "six hundred forty million, two hundred sixty-eight thousand, five hundred forty-four".