638616 has 64 divisors (see below), whose sum is σ = 1814400. Its totient is φ = 185600.

The previous prime is 638587. The next prime is 638621. The reversal of 638616 is 616836.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

638616 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 in 15 ways as a sum of consecutive naturals, for example, 10795 + ... + 10853.

It is an arithmetic number, because the mean of its divisors is an integer number (28350).

2⁶³⁸⁶¹⁶ is an apocalyptic number.

638616 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907200).

638616 is an abundant number, since it is smaller than the sum of its proper divisors (1175784).

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

638616 is a wasteful number, since it uses less digits than its factorization.

638616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120 (or 116 counting only the distinct ones).

The product of its digits is 5184, while the sum is 30.

The square root of 638616 is about 799.1345318531. The cubic root of 638616 is about 86.1152232360.

The spelling of 638616 in words is "six hundred thirty-eight thousand, six hundred sixteen".