638122 has 4 divisors (see below), whose sum is σ = 957186. Its totient is φ = 319060.

The previous prime is 638117. The next prime is 638123. The reversal of 638122 is 221836.

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

It can be written as a sum of positive squares in only one way, i.e., 594441 + 43681 = 771^2 + 209^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 638093 and 638102.

It is not an unprimeable number, because it can be changed into a prime (638123) by changing a digit.

638122 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 159529 + ... + 159532.

2⁶³⁸¹²² is an apocalyptic number.

638122 is a deficient number, since it is larger than the sum of its proper divisors (319064).

638122 is a wasteful number, since it uses less digits than its factorization.

638122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319063.

The product of its digits is 576, while the sum is 22.

The square root of 638122 is about 798.8253876787. The cubic root of 638122 is about 86.0930127610.

Adding to 638122 its reverse (221836), we get a palindrome (859958).

The spelling of 638122 in words is "six hundred thirty-eight thousand, one hundred twenty-two".