638223713 has 4 divisors (see below), whose sum is σ = 638363568. Its totient is φ = 638083860.

The previous prime is 638223701. The next prime is 638223731. The reversal of 638223713 is 317322836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638223713 - 2⁸ = 638223457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (638223913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62843 + ... + 72288.

It is an arithmetic number, because the mean of its divisors is an integer number (159590892).

Almost surely, 2^638223713 is an apocalyptic number.

It is an amenable number.

638223713 is a deficient number, since it is larger than the sum of its proper divisors (139855).

638223713 is a wasteful number, since it uses less digits than its factorization.

638223713 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139854.

The product of its digits is 36288, while the sum is 35.

The square root of 638223713 is about 25263.0899337353. The cubic root of 638223713 is about 860.9758676272.

The spelling of 638223713 in words is "six hundred thirty-eight million, two hundred twenty-three thousand, seven hundred thirteen".