638202240 has 320 divisors, whose sum is σ = 2457045360. Its totient is φ = 156930048.

The previous prime is 638202223. The next prime is 638202247. The reversal of 638202240 is 42202836.

638202240 is a `hidden beast` number, since 638 + 2 + 0 + 2 + 24 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (320).

It is a super-3 number, since 3×638202240³ (a number of 27 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638202247) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 673447 + ... + 674393.

Almost surely, 2^638202240 is an apocalyptic number.

638202240 is a gapful number since it is divisible by the number (60) 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 638202240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1228522680).

638202240 is an abundant number, since it is smaller than the sum of its proper divisors (1818843120).

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

638202240 is a wasteful number, since it uses less digits than its factorization.

638202240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 991 (or 970 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 638202240 is about 25262.6649425590. The cubic root of 638202240 is about 860.9662116911.

The spelling of 638202240 in words is "six hundred thirty-eight million, two hundred two thousand, two hundred forty".