638340845 has 16 divisors (see below), whose sum is σ = 773939712. Its totient is φ = 505414080.

The previous prime is 638340839. The next prime is 638340869. The reversal of 638340845 is 548043836.

It is a happy number.

638340845 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 638340845 - 2⁸ = 638340589 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 200234 + ... + 203396.

It is an arithmetic number, because the mean of its divisors is an integer number (48371232).

Almost surely, 2^638340845 is an apocalyptic number.

It is an amenable number.

638340845 is a deficient number, since it is larger than the sum of its proper divisors (135598867).

638340845 is a wasteful number, since it uses less digits than its factorization.

638340845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3572.

The product of its (nonzero) digits is 276480, while the sum is 41.

The square root of 638340845 is about 25265.4080711157. The cubic root of 638340845 is about 861.0285355002.

The spelling of 638340845 in words is "six hundred thirty-eight million, three hundred forty thousand, eight hundred forty-five".