206638 has 4 divisors (see below), whose sum is σ = 309960. Its totient is φ = 103318.

The previous prime is 206627. The next prime is 206639. The reversal of 206638 is 836602.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206639) by changing a digit.

206638 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51658 + ... + 51661.

It is an arithmetic number, because the mean of its divisors is an integer number (77490).

2²⁰⁶⁶³⁸ is an apocalyptic number.

206638 is a deficient number, since it is larger than the sum of its proper divisors (103322).

206638 is a wasteful number, since it uses less digits than its factorization.

206638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103321.

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

The square root of 206638 is about 454.5745263430. The cubic root of 206638 is about 59.1203137139.

The spelling of 206638 in words is "two hundred six thousand, six hundred thirty-eight".