21220121210 has 32 divisors (see below), whose sum is σ = 38591897472. Its totient is φ = 8400196800.

The previous prime is 21220121203. The next prime is 21220121297. The reversal of 21220121210 is 1212102212.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3494597 + ... + 3500663.

It is an arithmetic number, because the mean of its divisors is an integer number (1205996796).

Almost surely, 2^21220121210 is an apocalyptic number.

21220121210 is a deficient number, since it is larger than the sum of its proper divisors (17371776262).

21220121210 is a wasteful number, since it uses less digits than its factorization.

21220121210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9638.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21220121210 its reverse (1212102212), we get a palindrome (22432223422).

The spelling of 21220121210 in words is "twenty-one billion, two hundred twenty million, one hundred twenty-one thousand, two hundred ten".