638970 has 48 divisors (see below), whose sum is σ = 1645920. Its totient is φ = 158688.

The previous prime is 638959. The next prime is 638971. The reversal of 638970 is 79836.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638971) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10801 + ... + 10859.

It is an arithmetic number, because the mean of its divisors is an integer number (34290).

2⁶³⁸⁹⁷⁰ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638970, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822960).

638970 is an abundant number, since it is smaller than the sum of its proper divisors (1006950).

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

638970 is a wasteful number, since it uses less digits than its factorization.

638970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 33.

The square root of 638970 is about 799.3559907826. The cubic root of 638970 is about 86.1311322006.

The spelling of 638970 in words is "six hundred thirty-eight thousand, nine hundred seventy".