638601 has 4 divisors (see below), whose sum is σ = 851472. Its totient is φ = 425732.

The previous prime is 638587. The next prime is 638621. The reversal of 638601 is 106836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638601 - 2¹¹ = 636553 is a prime.

It is a super-2 number, since 2×638601² = 815622474402, which contains 22 as substring.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (638621) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 106431 + ... + 106436.

It is an arithmetic number, because the mean of its divisors is an integer number (212868).

2⁶³⁸⁶⁰¹ is an apocalyptic number.

It is an amenable number.

638601 is a deficient number, since it is larger than the sum of its proper divisors (212871).

638601 is a wasteful number, since it uses less digits than its factorization.

638601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212870.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 638601 is about 799.1251466448. The cubic root of 638601 is about 86.1145489975.

The spelling of 638601 in words is "six hundred thirty-eight thousand, six hundred one".