640263596544 has 240 divisors, whose sum is σ = 2170895991264. Its totient is φ = 179094528000.

The previous prime is 640263596509. The next prime is 640263596549. The reversal of 640263596544 is 445695362046.

640263596544 is a `hidden beast` number, since 6 + 4 + 0 + 2 + 6 + 3 + 5 + 96 + 544 = 666.

It is not an unprimeable number, because it can be changed into a prime (640263596549) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 173119 + ... + 1144769.

Almost surely, 2^640263596544 is an apocalyptic number.

640263596544 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 640263596544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1085447995632).

640263596544 is an abundant number, since it is smaller than the sum of its proper divisors (1530632394720).

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

640263596544 is a wasteful number, since it uses less digits than its factorization.

640263596544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 971699 (or 971680 counting only the distinct ones).

The product of its (nonzero) digits is 18662400, while the sum is 54.

The spelling of 640263596544 in words is "six hundred forty billion, two hundred sixty-three million, five hundred ninety-six thousand, five hundred forty-four".