21210121033 has 8 divisors (see below), whose sum is σ = 21332946888. Its totient is φ = 21087448704.

The previous prime is 21210121013. The next prime is 21210121067. The reversal of 21210121033 is 33012101212.

It can be written as a sum of positive squares in 4 ways, for example, as 16111732624 + 5098388409 = 126932^2 + 71403^2 .

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 21210121033 - 2¹⁷ = 21209989961 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21210120998 and 21210121016.

It is not an unprimeable number, because it can be changed into a prime (21210121013) 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, 244735 + ... + 319867.

It is an arithmetic number, because the mean of its divisors is an integer number (2666618361).

Almost surely, 2^21210121033 is an apocalyptic number.

It is an amenable number.

21210121033 is a deficient number, since it is larger than the sum of its proper divisors (122825855).

21210121033 is a wasteful number, since it uses less digits than its factorization.

21210121033 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76763.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21210121033 its reverse (33012101212), we get a palindrome (54222222245).

The spelling of 21210121033 in words is "twenty-one billion, two hundred ten million, one hundred twenty-one thousand, thirty-three".