638134380 has 288 divisors, whose sum is σ = 2269962240. Its totient is φ = 143700480.

The previous prime is 638134313. The next prime is 638134447. The reversal of 638134380 is 83431836.

It is a happy number.

638134380 is a `hidden beast` number, since 638 + 13 + 4 + 3 + 8 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (638134313) and next prime (638134447).

It is a Harshad number since it is a multiple of its sum of digits (36).

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 95 ways as a sum of consecutive naturals, for example, 1378029 + ... + 1378491.

Almost surely, 2^638134380 is an apocalyptic number.

638134380 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 638134380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1134981120).

638134380 is an abundant number, since it is smaller than the sum of its proper divisors (1631827860).

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

638134380 is a wasteful number, since it uses less digits than its factorization.

638134380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541 (or 536 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 638134380 is about 25261.3218181472. The cubic root of 638134380 is about 860.9356951169.

The spelling of 638134380 in words is "six hundred thirty-eight million, one hundred thirty-four thousand, three hundred eighty".