21031223020202 has 4 divisors (see below), whose sum is σ = 31546834530306. Its totient is φ = 10515611510100.

The previous prime is 21031223020169. The next prime is 21031223020207. The reversal of 21031223020202 is 20202032213012.

It is a happy number.

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., 19992961879801 + 1038261140401 = 4471349^2 + 1018951^2 .

It is not an unprimeable number, because it can be changed into a prime (21031223020207) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5257805755049 + ... + 5257805755052.

Almost surely, 2^{21031223020202} is an apocalyptic number.

21031223020202 is a deficient number, since it is larger than the sum of its proper divisors (10515611510104).

21031223020202 is a wasteful number, since it uses less digits than its factorization.

21031223020202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10515611510103.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21031223020202 its reverse (20202032213012), we get a palindrome (41233255233214).

The spelling of 21031223020202 in words is "twenty-one trillion, thirty-one billion, two hundred twenty-three million, twenty thousand, two hundred two".