206389139 has 16 divisors (see below), whose sum is σ = 229789440. Its totient is φ = 183785760.

The previous prime is 206389123. The next prime is 206389147. The reversal of 206389139 is 931983602.

It is a cyclic number.

It is not a de Polignac number, because 206389139 - 2⁴ = 206389123 is a prime.

It is a super-2 number, since 2×206389139² = 85192953394322642, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 206389096 and 206389105.

It is not an unprimeable number, because it can be changed into a prime (206389199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 315737 + ... + 316389.

It is an arithmetic number, because the mean of its divisors is an integer number (14361840).

Almost surely, 2^206389139 is an apocalyptic number.

206389139 is a deficient number, since it is larger than the sum of its proper divisors (23400301).

206389139 is a wasteful number, since it uses less digits than its factorization.

206389139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1210.

The product of its (nonzero) digits is 69984, while the sum is 41.

The square root of 206389139 is about 14366.2499978248. The cubic root of 206389139 is about 590.9657066134.

The spelling of 206389139 in words is "two hundred six million, three hundred eighty-nine thousand, one hundred thirty-nine".