21221101210 has 8 divisors (see below), whose sum is σ = 38197982196. Its totient is φ = 8488440480.

The previous prime is 21221101201. The next prime is 21221101211. The reversal of 21221101210 is 1210112212.

It can be written as a sum of positive squares in 2 ways, for example, as 18271199241 + 2949901969 = 135171^2 + 54313^2 .

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 (21221101211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1061055051 + ... + 1061055070.

Almost surely, 2^21221101210 is an apocalyptic number.

21221101210 is a deficient number, since it is larger than the sum of its proper divisors (16976880986).

21221101210 is a wasteful number, since it uses less digits than its factorization.

21221101210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2122110128.

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

Adding to 21221101210 its reverse (1210112212), we get a palindrome (22431213422).

The spelling of 21221101210 in words is "twenty-one billion, two hundred twenty-one million, one hundred one thousand, two hundred ten".