21131100211 has 16 divisors (see below), whose sum is σ = 24112963840. Its totient is φ = 18356608800.

The previous prime is 21131100203. The next prime is 21131100217. The reversal of 21131100211 is 11200113112.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21131100211 - 2³ = 21131100203 is a prime.

It is a super-2 number, since 2×21131100211² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a junction number, because it is equal to n+sod(n) for n = 21131100191 and 21131100200.

It is not an unprimeable number, because it can be changed into a prime (21131100217) 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, 245985 + ... + 320578.

It is an arithmetic number, because the mean of its divisors is an integer number (1507060240).

Almost surely, 2^21131100211 is an apocalyptic number.

21131100211 is a deficient number, since it is larger than the sum of its proper divisors (2981863629).

21131100211 is a wasteful number, since it uses less digits than its factorization.

21131100211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566746.

The product of its (nonzero) digits is 12, while the sum is 13.

Adding to 21131100211 its reverse (11200113112), we get a palindrome (32331213323).

The spelling of 21131100211 in words is "twenty-one billion, one hundred thirty-one million, one hundred thousand, two hundred eleven".