638587 has 2 divisors, whose sum is σ = 638588. Its totient is φ = 638586.

The previous prime is 638581. The next prime is 638621. The reversal of 638587 is 785836.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 638587 - 2⁷ = 638459 is a prime.

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

It is not a weakly prime, because it can be changed into another prime (638581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319293 + 319294.

It is an arithmetic number, because the mean of its divisors is an integer number (319294).

2⁶³⁸⁵⁸⁷ is an apocalyptic number.

638587 is a deficient number, since it is larger than the sum of its proper divisors (1).

638587 is an equidigital number, since it uses as much as digits as its factorization.

638587 is an evil number, because the sum of its binary digits is even.

The product of its digits is 40320, while the sum is 37.

The square root of 638587 is about 799.1163870176. The cubic root of 638587 is about 86.1139196987.

It can be divided in two parts, 638 and 587, that added together give a triangular number (1225 = T₄₉).

The spelling of 638587 in words is "six hundred thirty-eight thousand, five hundred eighty-seven".