21211211112 has 128 divisors (see below), whose sum is σ = 67029446400. Its totient is φ = 5442951168.

The previous prime is 21211211111. The next prime is 21211211123. The reversal of 21211211112 is 21111211212.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21211211091 and 21211211100.

It is not an unprimeable number, because it can be changed into a prime (21211211111) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50437 + ... + 212052.

It is an arithmetic number, because the mean of its divisors is an integer number (523667550).

Almost surely, 2^21211211112 is an apocalyptic number.

It is an amenable number.

21211211112 is an abundant number, since it is smaller than the sum of its proper divisors (45818235288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21211211112 is a wasteful number, since it uses less digits than its factorization.

21211211112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 262555 (or 262551 counting only the distinct ones).

The product of its digits is 16, while the sum is 15.

Adding to 21211211112 its reverse (21111211212), we get a palindrome (42322422324).

The spelling of 21211211112 in words is "twenty-one billion, two hundred eleven million, two hundred eleven thousand, one hundred twelve".