21211210123 has 8 divisors (see below), whose sum is σ = 21342170448. Its totient is φ = 21080346144.

The previous prime is 21211210109. The next prime is 21211210133. The reversal of 21211210123 is 32101211212.

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 21211210123 - 2²⁵ = 21177655691 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211210097 and 21211210106.

It is not an unprimeable number, because it can be changed into a prime (21211210103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 445665 + ... + 490957.

It is an arithmetic number, because the mean of its divisors is an integer number (2667771306).

Almost surely, 2^21211210123 is an apocalyptic number.

21211210123 is a deficient number, since it is larger than the sum of its proper divisors (130960325).

21211210123 is a wasteful number, since it uses less digits than its factorization.

21211210123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48173.

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 21211210123 its reverse (32101211212), we get a palindrome (53312421335).

The spelling of 21211210123 in words is "twenty-one billion, two hundred eleven million, two hundred ten thousand, one hundred twenty-three".