638787 has 8 divisors (see below), whose sum is σ = 864000. Its totient is φ = 419720.

The previous prime is 638767. The next prime is 638801. The reversal of 638787 is 787836.

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

It is a cyclic number.

It is not a de Polignac number, because 638787 - 2¹¹ = 636739 is a prime.

It is an alternating number because its digits alternate between even and odd.

638787 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638717) 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, 1287 + ... + 1712.

It is an arithmetic number, because the mean of its divisors is an integer number (108000).

2⁶³⁸⁷⁸⁷ is an apocalyptic number.

638787 is a deficient number, since it is larger than the sum of its proper divisors (225213).

638787 is a wasteful number, since it uses less digits than its factorization.

638787 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3073.

The product of its digits is 56448, while the sum is 39.

The square root of 638787 is about 799.2415154382. The cubic root of 638787 is about 86.1229088087.

The spelling of 638787 in words is "six hundred thirty-eight thousand, seven hundred eighty-seven".