21122012120123 has 4 divisors (see below), whose sum is σ = 21122445378720. Its totient is φ = 21121578861528.

The previous prime is 21122012120119. The next prime is 21122012120129. The reversal of 21122012120123 is 32102121022112.

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 21122012120123 - 2² = 21122012120119 is a prime.

It is a super-2 number, since 2×21122012120123² (a number of 27 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 = 21122012120095 and 21122012120104.

It is not an unprimeable number, because it can be changed into a prime (21122012120129) 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, 216556163 + ... + 216653676.

It is an arithmetic number, because the mean of its divisors is an integer number (5280611344680).

Almost surely, 2^{21122012120123} is an apocalyptic number.

21122012120123 is a deficient number, since it is larger than the sum of its proper divisors (433258597).

21122012120123 is an equidigital number, since it uses as much as digits as its factorization.

21122012120123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433258596.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 21122012120123 its reverse (32102121022112), we get a palindrome (53224133142235).

It can be divided in two parts, 2112201 and 2120123, that added together give a palindrome (4232324).

The spelling of 21122012120123 in words is "twenty-one trillion, one hundred twenty-two billion, twelve million, one hundred twenty thousand, one hundred twenty-three".