638256607 has 4 divisors (see below), whose sum is σ = 671849080. Its totient is φ = 604664136.

The previous prime is 638256587. The next prime is 638256649. The reversal of 638256607 is 706652836.

638256607 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 638256607 - 2¹¹ = 638254559 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638253607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16796208 + ... + 16796245.

It is an arithmetic number, because the mean of its divisors is an integer number (167962270).

Almost surely, 2^638256607 is an apocalyptic number.

638256607 is a deficient number, since it is larger than the sum of its proper divisors (33592473).

638256607 is a wasteful number, since it uses less digits than its factorization.

638256607 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33592472.

The product of its (nonzero) digits is 362880, while the sum is 43.

The square root of 638256607 is about 25263.7409541817. The cubic root of 638256607 is about 860.9906589159.

The spelling of 638256607 in words is "six hundred thirty-eight million, two hundred fifty-six thousand, six hundred seven".