638727223 has 4 divisors (see below), whose sum is σ = 638861688. Its totient is φ = 638592760.

The previous prime is 638727169. The next prime is 638727239. The reversal of 638727223 is 322727836.

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 638727223 - 2¹³ = 638719031 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638727623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 59836 + ... + 69697.

It is an arithmetic number, because the mean of its divisors is an integer number (159715422).

Almost surely, 2^638727223 is an apocalyptic number.

638727223 is a deficient number, since it is larger than the sum of its proper divisors (134465).

638727223 is a wasteful number, since it uses less digits than its factorization.

638727223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134464.

The product of its digits is 169344, while the sum is 40.

The square root of 638727223 is about 25273.0532979298. The cubic root of 638727223 is about 861.2022229516.

The spelling of 638727223 in words is "six hundred thirty-eight million, seven hundred twenty-seven thousand, two hundred twenty-three".