638611 has 4 divisors (see below), whose sum is σ = 640224. Its totient is φ = 637000.

The previous prime is 638587. The next prime is 638621. The reversal of 638611 is 116836.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 638611 - 2¹¹ = 636563 is a prime.

It is a Duffinian number.

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

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 246 + ... + 1156.

It is an arithmetic number, because the mean of its divisors is an integer number (160056).

2⁶³⁸⁶¹¹ is an apocalyptic number.

638611 is a deficient number, since it is larger than the sum of its proper divisors (1613).

638611 is an equidigital number, since it uses as much as digits as its factorization.

638611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612.

The product of its digits is 864, while the sum is 25.

The square root of 638611 is about 799.1314034625. The cubic root of 638611 is about 86.1149984910.

The spelling of 638611 in words is "six hundred thirty-eight thousand, six hundred eleven".