21121103233 has 4 divisors (see below), whose sum is σ = 21121514820. Its totient is φ = 21120691648.

The previous prime is 21121103197. The next prime is 21121103243. The reversal of 21121103233 is 33230112112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14950686529 + 6170416704 = 122273^2 + 78552^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21121103233 is a prime.

It is a super-2 number, since 2×21121103233² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21121103233.

It is not an unprimeable number, because it can be changed into a prime (21121103243) 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, 115660 + ... + 235837.

It is an arithmetic number, because the mean of its divisors is an integer number (5280378705).

Almost surely, 2^21121103233 is an apocalyptic number.

It is an amenable number.

21121103233 is a deficient number, since it is larger than the sum of its proper divisors (411587).

21121103233 is an equidigital number, since it uses as much as digits as its factorization.

21121103233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411586.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21121103233 its reverse (33230112112), we get a palindrome (54351215345).

The spelling of 21121103233 in words is "twenty-one billion, one hundred twenty-one million, one hundred three thousand, two hundred thirty-three".