640131648 has 112 divisors (see below), whose sum is σ = 1883030016. Its totient is φ = 190586880.

The previous prime is 640131619. The next prime is 640131649. The reversal of 640131648 is 846131046.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (640131649) 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 15 ways as a sum of consecutive naturals, for example, 73240 + ... + 81512.

It is an arithmetic number, because the mean of its divisors is an integer number (16812768).

Almost surely, 2^640131648 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640131648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (941515008).

640131648 is an abundant number, since it is smaller than the sum of its proper divisors (1242898368).

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

640131648 is a wasteful number, since it uses less digits than its factorization.

640131648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8332 (or 8322 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 640131648 is about 25300.8230696157. The cubic root of 640131648 is about 861.8329609238.

The spelling of 640131648 in words is "six hundred forty million, one hundred thirty-one thousand, six hundred forty-eight".