21251123110043 has 4 divisors (see below), whose sum is σ = 21251494554048. Its totient is φ = 21250751666040.

The previous prime is 21251123110001. The next prime is 21251123110057. The reversal of 21251123110043 is 34001132115212.

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 21251123110043 - 2¹⁶ = 21251123044507 is a prime.

It is a super-2 number, since 2×21251123110043² (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 = 21251123109994 and 21251123110021.

It is not an unprimeable number, because it can be changed into a prime (21251123110543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 185636171 + ... + 185750612.

It is an arithmetic number, because the mean of its divisors is an integer number (5312873638512).

Almost surely, 2^{21251123110043} is an apocalyptic number.

21251123110043 is a deficient number, since it is larger than the sum of its proper divisors (371444005).

21251123110043 is an equidigital number, since it uses as much as digits as its factorization.

21251123110043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371444004.

The product of its (nonzero) digits is 1440, while the sum is 26.

Adding to 21251123110043 its reverse (34001132115212), we get a palindrome (55252255225255).

The spelling of 21251123110043 in words is "twenty-one trillion, two hundred fifty-one billion, one hundred twenty-three million, one hundred ten thousand, forty-three".