638470224 has 480 divisors, whose sum is σ = 2381633280. Its totient is φ = 155271168.

The previous prime is 638470223. The next prime is 638470237. The reversal of 638470224 is 422074836.

It is a super-2 number, since 2×638470224² = 815288453869220352, which contains 22 as substring.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638470223) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12046582 + ... + 12046634.

It is an arithmetic number, because the mean of its divisors is an integer number (4961736).

Almost surely, 2^638470224 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 638470224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1190816640).

638470224 is an abundant number, since it is smaller than the sum of its proper divisors (1743163056).

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

638470224 is a wasteful number, since it uses less digits than its factorization.

638470224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 147 (or 138 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 36.

The square root of 638470224 is about 25267.9683393818. The cubic root of 638470224 is about 861.0867026934.

The spelling of 638470224 in words is "six hundred thirty-eight million, four hundred seventy thousand, two hundred twenty-four".