640322651168 has 162 divisors, whose sum is σ = 1373645031381. Its totient is φ = 293759791104.

The previous prime is 640322651161. The next prime is 640322651251. The reversal of 640322651168 is 861156223046.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 14 ways, for example, as 59940749584 + 580381901584 = 244828^2 + 761828^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=565828.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640322651161) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 4078488146 + ... + 4078488302.

Almost surely, 2^640322651168 is an apocalyptic number.

640322651168 is a gapful number since it is divisible by the number (68) 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 640322651168

640322651168 is an abundant number, since it is smaller than the sum of its proper divisors (733322380213).

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

640322651168 is an equidigital number, since it uses as much as digits as its factorization.

640322651168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464 (or 229 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 44.

The spelling of 640322651168 in words is "six hundred forty billion, three hundred twenty-two million, six hundred fifty-one thousand, one hundred sixty-eight".