21101212011 has 16 divisors (see below), whose sum is σ = 30712510080. Its totient is φ = 12780347520.

The previous prime is 21101211997. The next prime is 21101212031. The reversal of 21101212011 is 11021210112.

It is not a de Polignac number, because 21101212011 - 2¹¹ = 21101209963 is a prime.

It is a super-2 number, since 2×21101212011² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21101212031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 154621 + ... + 257118.

It is an arithmetic number, because the mean of its divisors is an integer number (1919531880).

Almost surely, 2^21101212011 is an apocalyptic number.

21101212011 is a deficient number, since it is larger than the sum of its proper divisors (9611298069).

21101212011 is a wasteful number, since it uses less digits than its factorization.

21101212011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413306.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 21101212011 its reverse (11021210112), we get a palindrome (32122422123).

It can be divided in two parts, 2110 and 1212011, that added together give a palindrome (1214121).

The spelling of 21101212011 in words is "twenty-one billion, one hundred one million, two hundred twelve thousand, eleven".