21111122011 has 8 divisors (see below), whose sum is σ = 24266460384. Its totient is φ = 17990649600.

The previous prime is 21111122003. The next prime is 21111122093. The reversal of 21111122011 is 11022111112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21111122011 - 2³ = 21111122003 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21111121982 and 21111122000.

It is not an unprimeable number, because it can be changed into a prime (21111122311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8715190 + ... + 8717611.

It is an arithmetic number, because the mean of its divisors is an integer number (3033307548).

Almost surely, 2^21111122011 is an apocalyptic number.

21111122011 is a deficient number, since it is larger than the sum of its proper divisors (3155338373).

21111122011 is a wasteful number, since it uses less digits than its factorization.

21111122011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17432981.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21111122011 its reverse (11022111112), we get a palindrome (32133233123).

The spelling of 21111122011 in words is "twenty-one billion, one hundred eleven million, one hundred twenty-two thousand, eleven".