21211111210 has 8 divisors (see below), whose sum is σ = 38180000196. Its totient is φ = 8484444480.

The previous prime is 21211111147. The next prime is 21211111253. The reversal of 21211111210 is 1211111212.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20551802881 + 659308329 = 143359^2 + 25677^2 .

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

It is a super-2 number, since 2×21211111210² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060555551 + ... + 1060555570.

Almost surely, 2^21211111210 is an apocalyptic number.

21211111210 is a deficient number, since it is larger than the sum of its proper divisors (16968888986).

21211111210 is a wasteful number, since it uses less digits than its factorization.

21211111210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2121111128.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21211111210 its reverse (1211111212), we get a palindrome (22422222422).

The spelling of 21211111210 in words is "twenty-one billion, two hundred eleven million, one hundred eleven thousand, two hundred ten".