638242142 has 4 divisors (see below), whose sum is σ = 957363216. Its totient is φ = 319121070.

The previous prime is 638242141. The next prime is 638242147. The reversal of 638242142 is 241242836.

638242142 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a junction number, because it is equal to n+sod(n) for n = 638242099 and 638242108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638242141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 159560534 + ... + 159560537.

It is an arithmetic number, because the mean of its divisors is an integer number (239340804).

Almost surely, 2^638242142 is an apocalyptic number.

638242142 is a deficient number, since it is larger than the sum of its proper divisors (319121074).

638242142 is a wasteful number, since it uses less digits than its factorization.

638242142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319121073.

The product of its digits is 18432, while the sum is 32.

The square root of 638242142 is about 25263.4546727086. The cubic root of 638242142 is about 860.9841545707.

Adding to 638242142 its reverse (241242836), we get a palindrome (879484978).

The spelling of 638242142 in words is "six hundred thirty-eight million, two hundred forty-two thousand, one hundred forty-two".