21251050123 has 8 divisors (see below), whose sum is σ = 22213994400. Its totient is φ = 20291354688.

The previous prime is 21251050111. The next prime is 21251050129. The reversal of 21251050123 is 32105015212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21251050123 - 2⁵ = 21251050091 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21251050094 and 21251050103.

It is not an unprimeable number, because it can be changed into a prime (21251050129) 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 7 ways as a sum of consecutive naturals, for example, 798828 + ... + 825001.

It is an arithmetic number, because the mean of its divisors is an integer number (2776749300).

Almost surely, 2^21251050123 is an apocalyptic number.

21251050123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21251050123 is a deficient number, since it is larger than the sum of its proper divisors (962944277).

21251050123 is a wasteful number, since it uses less digits than its factorization.

21251050123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1624421.

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 21251050123 its reverse (32105015212), we get a palindrome (53356065335).

The spelling of 21251050123 in words is "twenty-one billion, two hundred fifty-one million, fifty thousand, one hundred twenty-three".