638320023 has 48 divisors (see below), whose sum is σ = 1024452000. Its totient is φ = 379779840.

The previous prime is 638319971. The next prime is 638320031. The reversal of 638320023 is 320023836.

638320023 is a `hidden beast` number, since 638 + 3 + 2 + 0 + 0 + 23 = 666.

It is not a de Polignac number, because 638320023 - 2¹⁷ = 638188951 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638320093) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1607661 + ... + 1608057.

It is an arithmetic number, because the mean of its divisors is an integer number (21342750).

Almost surely, 2^638320023 is an apocalyptic number.

638320023 is a deficient number, since it is larger than the sum of its proper divisors (386131977).

638320023 is a wasteful number, since it uses less digits than its factorization.

638320023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 672 (or 669 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 638320023 is about 25264.9960023745. The cubic root of 638320023 is about 861.0191734532.

Adding to 638320023 its reverse (320023836), we get a palindrome (958343859).

The spelling of 638320023 in words is "six hundred thirty-eight million, three hundred twenty thousand, twenty-three".