21202106 has 4 divisors (see below), whose sum is σ = 31803162. Its totient is φ = 10601052.

The previous prime is 21202079. The next prime is 21202121. The reversal of 21202106 is 60120212.

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

It can be written as a sum of positive squares in only one way, i.e., 11498881 + 9703225 = 3391^2 + 3115^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5300525 + ... + 5300528.

Almost surely, 2^21202106 is an apocalyptic number.

21202106 is a deficient number, since it is larger than the sum of its proper divisors (10601056).

21202106 is a wasteful number, since it uses less digits than its factorization.

21202106 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10601055.

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21202106 is about 4604.5744645950. The cubic root of 21202106 is about 276.7746650189.

Adding to 21202106 its reverse (60120212), we get a palindrome (81322318).

The spelling of 21202106 in words is "twenty-one million, two hundred two thousand, one hundred six".