21211222011 has 16 divisors (see below), whose sum is σ = 32851730688. Its totient is φ = 11921997600.

The previous prime is 21211221991. The next prime is 21211222051. The reversal of 21211222011 is 11022211212.

It is not a de Polignac number, because 21211222011 - 2⁷ = 21211221883 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21211222051) 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, 8277885 + ... + 8280446.

It is an arithmetic number, because the mean of its divisors is an integer number (2053233168).

Almost surely, 2^21211222011 is an apocalyptic number.

21211222011 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21211222011 is a deficient number, since it is larger than the sum of its proper divisors (11640508677).

21211222011 is a wasteful number, since it uses less digits than its factorization.

21211222011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16558402.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21211222011 its reverse (11022211212), we get a palindrome (32233433223).

The spelling of 21211222011 in words is "twenty-one billion, two hundred eleven million, two hundred twenty-two thousand, eleven".