21102320121 has 8 divisors (see below), whose sum is σ = 28137124704. Its totient is φ = 14067864480.

The previous prime is 21102320111. The next prime is 21102320191. The reversal of 21102320121 is 12102320112.

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

It is not a de Polignac number, because 21102320121 - 2¹⁰ = 21102319097 is a prime.

It is a super-2 number, since 2×21102320121² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21102320121.

It is not an unprimeable number, because it can be changed into a prime (21102320101) 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, 134110 + ... + 245336.

It is an arithmetic number, because the mean of its divisors is an integer number (3517140588).

Almost surely, 2^21102320121 is an apocalyptic number.

It is an amenable number.

21102320121 is a deficient number, since it is larger than the sum of its proper divisors (7034804583).

21102320121 is a wasteful number, since it uses less digits than its factorization.

21102320121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174471.

The product of its (nonzero) digits is 48, while the sum is 15.

Adding to 21102320121 its reverse (12102320112), we get a palindrome (33204640233).

Subtracting from 21102320121 its reverse (12102320112), we obtain a palindrome (9000000009).

The spelling of 21102320121 in words is "twenty-one billion, one hundred two million, three hundred twenty thousand, one hundred twenty-one".