638143 has 4 divisors (see below), whose sum is σ = 696168. Its totient is φ = 580120.

The previous prime is 638123. The next prime is 638147. The reversal of 638143 is 341836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638143 - 2¹⁷ = 507071 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638147) 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, 28996 + ... + 29017.

It is an arithmetic number, because the mean of its divisors is an integer number (174042).

2⁶³⁸¹⁴³ is an apocalyptic number.

638143 is a deficient number, since it is larger than the sum of its proper divisors (58025).

638143 is a wasteful number, since it uses less digits than its factorization.

638143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58024.

The product of its digits is 1728, while the sum is 25.

The square root of 638143 is about 798.8385318699. The cubic root of 638143 is about 86.0939571642.

Adding to 638143 its reverse (341836), we get a palindrome (979979).

The spelling of 638143 in words is "six hundred thirty-eight thousand, one hundred forty-three".