21121222011 has 12 divisors (see below), whose sum is σ = 28422411192. Its totient is φ = 13951609344.

The previous prime is 21121222009. The next prime is 21121222049. The reversal of 21121222011 is 11022212112.

It is not a de Polignac number, because 21121222011 - 2¹ = 21121222009 is a prime.

It is a super-2 number, since 2×21121222011² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121222081) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 260646 + ... + 331931.

It is an arithmetic number, because the mean of its divisors is an integer number (2368534266).

Almost surely, 2^21121222011 is an apocalyptic number.

21121222011 is a deficient number, since it is larger than the sum of its proper divisors (7301189181).

21121222011 is an equidigital number, since it uses as much as digits as its factorization.

21121222011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 592798 (or 592689 counting only the distinct ones).

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

Adding to 21121222011 its reverse (11022212112), we get a palindrome (32143434123).

The spelling of 21121222011 in words is "twenty-one billion, one hundred twenty-one million, two hundred twenty-two thousand, eleven".