638158127 has 4 divisors (see below), whose sum is σ = 638230320. Its totient is φ = 638085936.

The previous prime is 638158099. The next prime is 638158139. The reversal of 638158127 is 721851836.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 638158127 - 2¹² = 638154031 is a prime.

It is a super-2 number, since 2×638158127² = 814491590112296258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638151127) 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, 20627 + ... + 41252.

It is an arithmetic number, because the mean of its divisors is an integer number (159557580).

Almost surely, 2^638158127 is an apocalyptic number.

638158127 is a deficient number, since it is larger than the sum of its proper divisors (72193).

638158127 is a wasteful number, since it uses less digits than its factorization.

638158127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72192.

The product of its digits is 80640, while the sum is 41.

The square root of 638158127 is about 25261.7918406435. The cubic root of 638158127 is about 860.9463743651.

The spelling of 638158127 in words is "six hundred thirty-eight million, one hundred fifty-eight thousand, one hundred twenty-seven".