638448648 has 16 divisors (see below), whose sum is σ = 1596121680. Its totient is φ = 212816208.

The previous prime is 638448641. The next prime is 638448661. The reversal of 638448648 is 846844836.

It is a super-2 number, since 2×638448648² = 815233352266055808, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 638448648.

It is not an unprimeable number, because it can be changed into a prime (638448641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13300990 + ... + 13301037.

It is an arithmetic number, because the mean of its divisors is an integer number (99757605).

Almost surely, 2^638448648 is an apocalyptic number.

It is an amenable number.

638448648 is an abundant number, since it is smaller than the sum of its proper divisors (957673032).

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

638448648 is a wasteful number, since it uses less digits than its factorization.

638448648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26602036 (or 26602032 counting only the distinct ones).

The product of its digits is 3538944, while the sum is 51.

The square root of 638448648 is about 25267.5413920706. The cubic root of 638448648 is about 861.0770029374.

The spelling of 638448648 in words is "six hundred thirty-eight million, four hundred forty-eight thousand, six hundred forty-eight".