21221020202 has 8 divisors (see below), whose sum is σ = 33703973316. Its totient is φ = 9986362432.

The previous prime is 21221020201. The next prime is 21221020217. The reversal of 21221020202 is 20202012212.

It can be written as a sum of positive squares in 2 ways, for example, as 19569491881 + 1651528321 = 139891^2 + 40639^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21221020201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312073793 + ... + 312073860.

Almost surely, 2^21221020202 is an apocalyptic number.

21221020202 is a deficient number, since it is larger than the sum of its proper divisors (12482953114).

21221020202 is a wasteful number, since it uses less digits than its factorization.

21221020202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624147672.

The product of its (nonzero) digits is 64, while the sum is 14.

Adding to 21221020202 its reverse (20202012212), we get a palindrome (41423032414).

The spelling of 21221020202 in words is "twenty-one billion, two hundred twenty-one million, twenty thousand, two hundred two".