21122012111 has 4 divisors (see below), whose sum is σ = 21571416672. Its totient is φ = 20672607552.

The previous prime is 21122012053. The next prime is 21122012123. The reversal of 21122012111 is 11121022112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21122012111 - 2¹⁰ = 21122011087 is a prime.

It is a super-2 number, since 2×21122012111² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122012911) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 224702210 + ... + 224702303.

It is an arithmetic number, because the mean of its divisors is an integer number (5392854168).

Almost surely, 2^21122012111 is an apocalyptic number.

21122012111 is a deficient number, since it is larger than the sum of its proper divisors (449404561).

21122012111 is an equidigital number, since it uses as much as digits as its factorization.

21122012111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 449404560.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21122012111 its reverse (11121022112), we get a palindrome (32243034223).

The spelling of 21122012111 in words is "twenty-one billion, one hundred twenty-two million, twelve thousand, one hundred eleven".