21122323511 has 4 divisors (see below), whose sum is σ = 21127270992. Its totient is φ = 21117376032.

The previous prime is 21122323483. The next prime is 21122323531. The reversal of 21122323511 is 11532322112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21122323511 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122323531) 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, 2467331 + ... + 2475876.

It is an arithmetic number, because the mean of its divisors is an integer number (5281817748).

Almost surely, 2^21122323511 is an apocalyptic number.

21122323511 is a deficient number, since it is larger than the sum of its proper divisors (4947481).

21122323511 is an equidigital number, since it uses as much as digits as its factorization.

21122323511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4947480.

The product of its digits is 720, while the sum is 23.

Adding to 21122323511 its reverse (11532322112), we get a palindrome (32654645623).

The spelling of 21122323511 in words is "twenty-one billion, one hundred twenty-two million, three hundred twenty-three thousand, five hundred eleven".