640385748544 has 28 divisors (see below), whose sum is σ = 1275255843184. Its totient is φ = 319061441664.

The previous prime is 640385748523. The next prime is 640385748547. The reversal of 640385748544 is 445847583046.

It is not an unprimeable number, because it can be changed into a prime (640385748547) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17660382 + ... + 17696605.

Almost surely, 2^640385748544 is an apocalyptic number.

640385748544 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

640385748544 is a deficient number, since it is larger than the sum of its proper divisors (634870094640).

640385748544 is a wasteful number, since it uses less digits than its factorization.

640385748544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35357282 (or 35357272 counting only the distinct ones).

The product of its (nonzero) digits is 51609600, while the sum is 58.

The spelling of 640385748544 in words is "six hundred forty billion, three hundred eighty-five million, seven hundred forty-eight thousand, five hundred forty-four".