640444204426 has 32 divisors (see below), whose sum is σ = 1036059010560. Its totient is φ = 295162698816.

The previous prime is 640444204423. The next prime is 640444204447. The reversal of 640444204426 is 624402444046.

It is a happy number.

640444204426 is nontrivially palindromic in base 12.

It is not an unprimeable number, because it can be changed into a prime (640444204423) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77278855 + ... + 77287141.

It is an arithmetic number, because the mean of its divisors is an integer number (32376844080).

Almost surely, 2^640444204426 is an apocalyptic number.

640444204426 is a deficient number, since it is larger than the sum of its proper divisors (395614806134).

640444204426 is a wasteful number, since it uses less digits than its factorization.

640444204426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12238.

The product of its (nonzero) digits is 589824, while the sum is 40.

The spelling of 640444204426 in words is "six hundred forty billion, four hundred forty-four million, two hundred four thousand, four hundred twenty-six".