21101220211 has 8 divisors (see below), whose sum is σ = 22022885664. Its totient is φ = 20179906560.

The previous prime is 21101220209. The next prime is 21101220253. The reversal of 21101220211 is 11202210112.

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

It is a cyclic number.

It is not a de Polignac number, because 21101220211 - 2¹ = 21101220209 is a prime.

It is a super-2 number, since 2×21101220211² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21101220191 and 21101220200.

It is not an unprimeable number, because it can be changed into a prime (21101220311) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 38515 + ... + 209011.

It is an arithmetic number, because the mean of its divisors is an integer number (2752860708).

Almost surely, 2^21101220211 is an apocalyptic number.

21101220211 is a deficient number, since it is larger than the sum of its proper divisors (921665453).

21101220211 is a wasteful number, since it uses less digits than its factorization.

21101220211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175901.

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

Adding to 21101220211 its reverse (11202210112), we get a palindrome (32303430323).

The spelling of 21101220211 in words is "twenty-one billion, one hundred one million, two hundred twenty thousand, two hundred eleven".