21110123121 has 8 divisors (see below), whose sum is σ = 28164662880. Its totient is φ = 14064499392.

The previous prime is 21110123119. The next prime is 21110123161. The reversal of 21110123121 is 12132101112.

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

It is not a de Polignac number, because 21110123121 - 2¹ = 21110123119 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21110123121.

It is not an unprimeable number, because it can be changed into a prime (21110123161) 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, 2223480 + ... + 2232953.

It is an arithmetic number, because the mean of its divisors is an integer number (3520582860).

Almost surely, 2^21110123121 is an apocalyptic number.

It is an amenable number.

21110123121 is a deficient number, since it is larger than the sum of its proper divisors (7054539759).

21110123121 is a wasteful number, since it uses less digits than its factorization.

21110123121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4458015.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 21110123121 its reverse (12132101112), we get a palindrome (33242224233).

The spelling of 21110123121 in words is "twenty-one billion, one hundred ten million, one hundred twenty-three thousand, one hundred twenty-one".