21111222122011 has 4 divisors (see below), whose sum is σ = 24127110996592. Its totient is φ = 18095333247432.

The previous prime is 21111222121973. The next prime is 21111222122017. The reversal of 21111222122011 is 11022122211112.

It is a happy number.

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

It is not a de Polignac number, because 21111222122011 - 2²¹ = 21111220024859 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21111222122011.

It is not an unprimeable number, because it can be changed into a prime (21111222122017) 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, 1507944437280 + ... + 1507944437293.

It is an arithmetic number, because the mean of its divisors is an integer number (6031777749148).

Almost surely, 2^{21111222122011} is an apocalyptic number.

21111222122011 is a deficient number, since it is larger than the sum of its proper divisors (3015888874581).

21111222122011 is an equidigital number, since it uses as much as digits as its factorization.

21111222122011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3015888874580.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21111222122011 its reverse (11022122211112), we get a palindrome (32133344333123).

The spelling of 21111222122011 in words is "twenty-one trillion, one hundred eleven billion, two hundred twenty-two million, one hundred twenty-two thousand, eleven".