206110021 has 4 divisors (see below), whose sum is σ = 221964652. Its totient is φ = 190255392.

The previous prime is 206110007. The next prime is 206110031. The reversal of 206110021 is 120011602.

206110021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 38925121 + 167184900 = 6239^2 + 12930^2 .

It is a cyclic number.

It is not a de Polignac number, because 206110021 - 2¹⁹ = 205585733 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13), and also a Moran number because the ratio is a prime number: 15854617 = 206110021 / (2 + 0 + 6 + 1 + 1 + 0 + 0 + 2 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 206109983 and 206110010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (206110031) 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, 7927296 + ... + 7927321.

It is an arithmetic number, because the mean of its divisors is an integer number (55491163).

Almost surely, 2^206110021 is an apocalyptic number.

It is an amenable number.

206110021 is a deficient number, since it is larger than the sum of its proper divisors (15854631).

206110021 is a wasteful number, since it uses less digits than its factorization.

206110021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15854630.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 206110021 is about 14356.5323459393. The cubic root of 206110021 is about 590.6991816383.

Adding to 206110021 its reverse (120011602), we get a palindrome (326121623).

The spelling of 206110021 in words is "two hundred six million, one hundred ten thousand, twenty-one".