640140643450 has 96 divisors (see below), whose sum is σ = 1485323683200. Its totient is φ = 199408435200.

The previous prime is 640140643403. The next prime is 640140643463. The reversal of 640140643450 is 54346041046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6701626 + ... + 6796474.

It is an arithmetic number, because the mean of its divisors is an integer number (15472121700).

Almost surely, 2^640140643450 is an apocalyptic number.

640140643450 is an abundant number, since it is smaller than the sum of its proper divisors (845183039750).

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

640140643450 is a wasteful number, since it uses less digits than its factorization.

640140643450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96632 (or 96627 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 37.

Adding to 640140643450 its reverse (54346041046), we get a palindrome (694486684496).

The spelling of 640140643450 in words is "six hundred forty billion, one hundred forty million, six hundred forty-three thousand, four hundred fifty".