638675268 has 144 divisors (see below), whose sum is σ = 1933381632. Its totient is φ = 160459200.

The previous prime is 638675251. The next prime is 638675309. The reversal of 638675268 is 862576836.

It is a self number, because there is not a number n which added to its sum of digits gives 638675268.

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 47 ways as a sum of consecutive naturals, for example, 314071 + ... + 316097.

Almost surely, 2^638675268 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 638675268, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (966690816).

638675268 is an abundant number, since it is smaller than the sum of its proper divisors (1294706364).

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

638675268 is a wasteful number, since it uses less digits than its factorization.

638675268 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2094 (or 2081 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 51.

The square root of 638675268 is about 25272.0254035960. The cubic root of 638675268 is about 861.1788718386.

The spelling of 638675268 in words is "six hundred thirty-eight million, six hundred seventy-five thousand, two hundred sixty-eight".