21123000211 has 4 divisors (see below), whose sum is σ = 21175676424. Its totient is φ = 21070324000.

The previous prime is 21123000187. The next prime is 21123000229. The reversal of 21123000211 is 11200032112.

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 21123000211 - 2⁹ = 21122999699 is a prime.

It is a super-2 number, since 2×21123000211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21123000191 and 21123000200.

It is not an unprimeable number, because it can be changed into a prime (21123000281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26337505 + ... + 26338306.

It is an arithmetic number, because the mean of its divisors is an integer number (5293919106).

Almost surely, 2^21123000211 is an apocalyptic number.

21123000211 is a deficient number, since it is larger than the sum of its proper divisors (52676213).

21123000211 is an equidigital number, since it uses as much as digits as its factorization.

21123000211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52676212.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21123000211 its reverse (11200032112), we get a palindrome (32323032323).

The spelling of 21123000211 in words is "twenty-one billion, one hundred twenty-three million, two hundred eleven", and thus it is an aban number.