638475696 has 280 divisors, whose sum is σ = 2027558720. Its totient is φ = 193995648.

The previous prime is 638475671. The next prime is 638475697. The reversal of 638475696 is 696574836.

638475696 is a `hidden beast` number, since 6 + 38 + 47 + 569 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (638475697) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 9529455 + ... + 9529521.

Almost surely, 2^638475696 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 638475696, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1013779360).

638475696 is an abundant number, since it is smaller than the sum of its proper divisors (1389083024).

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

638475696 is a wasteful number, since it uses less digits than its factorization.

638475696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 134 counting only the distinct ones).

The product of its digits is 6531840, while the sum is 54.

The square root of 638475696 is about 25268.0766185319. The cubic root of 638475696 is about 861.0891626634.

The spelling of 638475696 in words is "six hundred thirty-eight million, four hundred seventy-five thousand, six hundred ninety-six".