206138 has 4 divisors (see below), whose sum is σ = 309210. Its totient is φ = 103068.

The previous prime is 206123. The next prime is 206153. The reversal of 206138 is 831602.

206138 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 831602 = 2 ⋅415801.

It is an interprime number because it is at equal distance from previous prime (206123) and next prime (206153).

It can be written as a sum of positive squares in only one way, i.e., 142129 + 64009 = 377^2 + 253^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51533 + ... + 51536.

2²⁰⁶¹³⁸ is an apocalyptic number.

206138 is a deficient number, since it is larger than the sum of its proper divisors (103072).

206138 is a wasteful number, since it uses less digits than its factorization.

206138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103071.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 206138 is about 454.0242284284. The cubic root of 206138 is about 59.0725909151.

It can be divided in two parts, 20 and 6138, that multiplied together give a triangular number (122760 = T₄₉₅).

The spelling of 206138 in words is "two hundred six thousand, one hundred thirty-eight".