638004642 has 48 divisors (see below), whose sum is σ = 1416513312. Its totient is φ = 189989440.

The previous prime is 638004641. The next prime is 638004671. The reversal of 638004642 is 246400836.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (638004641) 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 23 ways as a sum of consecutive naturals, for example, 228358 + ... + 231134.

It is an arithmetic number, because the mean of its divisors is an integer number (29510694).

Almost surely, 2^638004642 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638004642, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (708256656).

638004642 is an abundant number, since it is smaller than the sum of its proper divisors (778508670).

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

638004642 is a wasteful number, since it uses less digits than its factorization.

638004642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2911 (or 2852 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 638004642 is about 25258.7537697330. The cubic root of 638004642 is about 860.8773460454.

The spelling of 638004642 in words is "six hundred thirty-eight million, four thousand, six hundred forty-two".