21320110121 has 4 divisors (see below), whose sum is σ = 22442221200. Its totient is φ = 20197999044.

The previous prime is 21320110117. The next prime is 21320110181. The reversal of 21320110121 is 12101102312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21320110121 - 2² = 21320110117 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21320110096 and 21320110105.

It is not an unprimeable number, because it can be changed into a prime (21320110181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561055511 + ... + 561055548.

It is an arithmetic number, because the mean of its divisors is an integer number (5610555300).

Almost surely, 2^21320110121 is an apocalyptic number.

It is an amenable number.

21320110121 is a deficient number, since it is larger than the sum of its proper divisors (1122111079).

21320110121 is a wasteful number, since it uses less digits than its factorization.

21320110121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122111078.

The product of its (nonzero) digits is 24, while the sum is 14.

Adding to 21320110121 its reverse (12101102312), we get a palindrome (33421212433).

It can be divided in two parts, 213201 and 10121, that added together give a palindrome (223322).

The spelling of 21320110121 in words is "twenty-one billion, three hundred twenty million, one hundred ten thousand, one hundred twenty-one".