21050206 has 8 divisors (see below), whose sum is σ = 31625064. Its totient is φ = 10508520.

The previous prime is 21050203. The next prime is 21050231. The reversal of 21050206 is 60205012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21050206² = 886222345284872, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21050206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050203) 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, 6640 + ... + 9283.

It is an arithmetic number, because the mean of its divisors is an integer number (3953133).

Almost surely, 2^21050206 is an apocalyptic number.

21050206 is a deficient number, since it is larger than the sum of its proper divisors (10574858).

21050206 is a wasteful number, since it uses less digits than its factorization.

21050206 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16586.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 21050206 is about 4588.0503484596. The cubic root of 21050206 is about 276.1121070166.

Adding to 21050206 its reverse (60205012), we get a palindrome (81255218).

The spelling of 21050206 in words is "twenty-one million, fifty thousand, two hundred six".