638787243 has 8 divisors (see below), whose sum is σ = 853800400. Its totient is φ = 424816128.

The previous prime is 638787241. The next prime is 638787269. The reversal of 638787243 is 342787836.

638787243 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638787243 - 2¹ = 638787241 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638787192 and 638787201.

It is not an unprimeable number, because it can be changed into a prime (638787241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 259078 + ... + 261531.

It is an arithmetic number, because the mean of its divisors is an integer number (106725050).

Almost surely, 2^638787243 is an apocalyptic number.

638787243 is a deficient number, since it is larger than the sum of its proper divisors (215013157).

638787243 is a wasteful number, since it uses less digits than its factorization.

638787243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521021.

The product of its digits is 1354752, while the sum is 48.

The square root of 638787243 is about 25274.2407007609. The cubic root of 638787243 is about 861.2291972930.

The spelling of 638787243 in words is "six hundred thirty-eight million, seven hundred eighty-seven thousand, two hundred forty-three".