21120133123 has 4 divisors (see below), whose sum is σ = 21120546600. Its totient is φ = 21119719648.

The previous prime is 21120133117. The next prime is 21120133201. The reversal of 21120133123 is 32133102112.

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 21120133123 - 2⁹ = 21120132611 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 21120133123.

It is not an unprimeable number, because it can be changed into a prime (21120133523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117190 + ... + 236587.

It is an arithmetic number, because the mean of its divisors is an integer number (5280136650).

Almost surely, 2^21120133123 is an apocalyptic number.

21120133123 is a deficient number, since it is larger than the sum of its proper divisors (413477).

21120133123 is an equidigital number, since it uses as much as digits as its factorization.

21120133123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 413476.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21120133123 its reverse (32133102112), we get a palindrome (53253235235).

The spelling of 21120133123 in words is "twenty-one billion, one hundred twenty million, one hundred thirty-three thousand, one hundred twenty-three".