206424139 has 4 divisors (see below), whose sum is σ = 206581024. Its totient is φ = 206267256.

The previous prime is 206424109. The next prime is 206424143. The reversal of 206424139 is 931424602.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 931424602 = 2 ⋅465712301.

It is a cyclic number.

It is not a de Polignac number, because 206424139 - 2⁵ = 206424107 is a prime.

It is a super-2 number, since 2×206424139² = 85221850323782642, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 206424139.

It is not an unprimeable number, because it can be changed into a prime (206424109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76452 + ... + 79105.

It is an arithmetic number, because the mean of its divisors is an integer number (51645256).

Almost surely, 2^206424139 is an apocalyptic number.

206424139 is a deficient number, since it is larger than the sum of its proper divisors (156885).

206424139 is a wasteful number, since it uses less digits than its factorization.

206424139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156884.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 206424139 is about 14367.4680789623. The cubic root of 206424139 is about 590.9991105524. Note that the first 3 decimals are identical.

The spelling of 206424139 in words is "two hundred six million, four hundred twenty-four thousand, one hundred thirty-nine".