638187480 has 192 divisors, whose sum is σ = 2510015040. Its totient is φ = 137281536.

The previous prime is 638187461. The next prime is 638187481. The reversal of 638187480 is 84781836.

638187480 is a `hidden beast` number, since 638 + 1 + 8 + 7 + 4 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638187481) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 35392 + ... + 50288.

It is an arithmetic number, because the mean of its divisors is an integer number (13072995).

Almost surely, 2^638187480 is an apocalyptic number.

638187480 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 638187480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1255007520).

638187480 is an abundant number, since it is smaller than the sum of its proper divisors (1871827560).

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

638187480 is a wasteful number, since it uses less digits than its factorization.

638187480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14938 (or 14931 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 638187480 is about 25262.3728101697. The cubic root of 638187480 is about 860.9595743179.

The spelling of 638187480 in words is "six hundred thirty-eight million, one hundred eighty-seven thousand, four hundred eighty".