638730 has 48 divisors (see below), whose sum is σ = 1707264. Its totient is φ = 165600.

The previous prime is 638719. The next prime is 638767. The reversal of 638730 is 37836.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 638694 and 638703.

It is an unprimeable 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 23 ways as a sum of consecutive naturals, for example, 4155 + ... + 4305.

It is an arithmetic number, because the mean of its divisors is an integer number (35568).

2⁶³⁸⁷³⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638730, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (853632).

638730 is an abundant number, since it is smaller than the sum of its proper divisors (1068534).

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

638730 is a wasteful number, since it uses less digits than its factorization.

638730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 208 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 27.

The square root of 638730 is about 799.2058558344. The cubic root of 638730 is about 86.1203471035.

The spelling of 638730 in words is "six hundred thirty-eight thousand, seven hundred thirty".