638420142 has 32 divisors (see below), whose sum is σ = 1353112992. Its totient is φ = 200116224.

The previous prime is 638420119. The next prime is 638420149. The reversal of 638420142 is 241024836.

It is a super-2 number, since 2×638420142² = 815160555422600328, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638420149) 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 15 ways as a sum of consecutive naturals, for example, 170838 + ... + 174534.

It is an arithmetic number, because the mean of its divisors is an integer number (42284781).

Almost surely, 2^638420142 is an apocalyptic number.

638420142 is an abundant number, since it is smaller than the sum of its proper divisors (714692850).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638420142 is a wasteful number, since it uses less digits than its factorization.

638420142 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5412.

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 638420142 is about 25266.9773024001. The cubic root of 638420142 is about 861.0641873798.

Adding to 638420142 its reverse (241024836), we get a palindrome (879444978).

The spelling of 638420142 in words is "six hundred thirty-eight million, four hundred twenty thousand, one hundred forty-two".