638546004 has 60 divisors (see below), whose sum is σ = 1680051604. Its totient is φ = 211476096.

The previous prime is 638545997. The next prime is 638546059. The reversal of 638546004 is 400645836.

It can be written as a sum of positive squares in 2 ways, for example, as 477509904 + 161036100 = 21852^2 + 12690^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 638546004.

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 44592 + ... + 57144.

Almost surely, 2^638546004 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638546004, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (840025802).

638546004 is an abundant number, since it is smaller than the sum of its proper divisors (1041505600).

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

638546004 is a wasteful number, since it uses less digits than its factorization.

638546004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12726 (or 12715 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 638546004 is about 25269.4678218596. The cubic root of 638546004 is about 861.1207687920.

The spelling of 638546004 in words is "six hundred thirty-eight million, five hundred forty-six thousand, four".