21231241121 has 4 divisors (see below), whose sum is σ = 21234154032. Its totient is φ = 21228328212.

The previous prime is 21231241103. The next prime is 21231241159. The reversal of 21231241121 is 12114213212.

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 a de Polignac number, because none of the positive numbers 2^k-21231241121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231241093 and 21231241102.

It is not an unprimeable number, because it can be changed into a prime (21231241021) 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, 1445495 + ... + 1460108.

It is an arithmetic number, because the mean of its divisors is an integer number (5308538508).

Almost surely, 2^21231241121 is an apocalyptic number.

It is an amenable number.

21231241121 is a deficient number, since it is larger than the sum of its proper divisors (2912911).

21231241121 is an equidigital number, since it uses as much as digits as its factorization.

21231241121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2912910.

The product of its digits is 192, while the sum is 20.

Adding to 21231241121 its reverse (12114213212), we get a palindrome (33345454333).

The spelling of 21231241121 in words is "twenty-one billion, two hundred thirty-one million, two hundred forty-one thousand, one hundred twenty-one".