638421120 has 384 divisors, whose sum is σ = 2367705600. Its totient is φ = 158146560.

The previous prime is 638421107. The next prime is 638421131. The reversal of 638421120 is 21124836.

638421120 is a `hidden beast` number, since 638 + 4 + 2 + 1 + 1 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 8081241 + ... + 8081319.

It is an arithmetic number, because the mean of its divisors is an integer number (6165900).

Almost surely, 2^638421120 is an apocalyptic number.

638421120 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 638421120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1183852800).

638421120 is an abundant number, since it is smaller than the sum of its proper divisors (1729284480).

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

638421120 is a wasteful number, since it uses less digits than its factorization.

638421120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188 (or 173 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 638421120 is about 25266.9966557167. The cubic root of 638421120 is about 861.0646270695.

Adding to 638421120 its reverse (21124836), we get a palindrome (659545956).

The spelling of 638421120 in words is "six hundred thirty-eight million, four hundred twenty-one thousand, one hundred twenty".