638396478206 has 4 divisors (see below), whose sum is σ = 957594717312. Its totient is φ = 319198239102.

The previous prime is 638396478197. The next prime is 638396478259. The reversal of 638396478206 is 602874693836.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159599119550 + ... + 159599119553.

It is an arithmetic number, because the mean of its divisors is an integer number (239398679328).

Almost surely, 2^638396478206 is an apocalyptic number.

638396478206 is a deficient number, since it is larger than the sum of its proper divisors (319198239106).

638396478206 is a wasteful number, since it uses less digits than its factorization.

638396478206 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319198239105.

The product of its (nonzero) digits is 62705664, while the sum is 62.

The spelling of 638396478206 in words is "six hundred thirty-eight billion, three hundred ninety-six million, four hundred seventy-eight thousand, two hundred six".