638571 has 16 divisors (see below), whose sum is σ = 950400. Its totient is φ = 379008.

The previous prime is 638567. The next prime is 638581. The reversal of 638571 is 175836.

638571 = T₁₆₄ + T₁₆₅ + ... + T₂₀₁.

It is not a de Polignac number, because 638571 - 2² = 638567 is a prime.

638571 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (638501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 640 + ... + 1298.

It is an arithmetic number, because the mean of its divisors is an integer number (59400).

2⁶³⁸⁵⁷¹ is an apocalyptic number.

638571 is a deficient number, since it is larger than the sum of its proper divisors (311829).

638571 is a wasteful number, since it uses less digits than its factorization.

638571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 698.

The product of its digits is 5040, while the sum is 30.

The square root of 638571 is about 799.1063758975. The cubic root of 638571 is about 86.1132004889.

The spelling of 638571 in words is "six hundred thirty-eight thousand, five hundred seventy-one".