21220111210 has 32 divisors (see below), whose sum is σ = 38417624784. Its totient is φ = 8438976000.

The previous prime is 21220111181. The next prime is 21220111223. The reversal of 21220111210 is 1211102212.

It can be written as a sum of positive squares in 8 ways, for example, as 2167554249 + 19052556961 = 46557^2 + 138031^2 .

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 1287220 + ... + 1303600.

Almost surely, 2^21220111210 is an apocalyptic number.

21220111210 is a deficient number, since it is larger than the sum of its proper divisors (17197513574).

21220111210 is a wasteful number, since it uses less digits than its factorization.

21220111210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17130.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21220111210 its reverse (1211102212), we get a palindrome (22431213422).

The spelling of 21220111210 in words is "twenty-one billion, two hundred twenty million, one hundred eleven thousand, two hundred ten".