21210331133 has 4 divisors (see below), whose sum is σ = 21211208220. Its totient is φ = 21209454048.

The previous prime is 21210331111. The next prime is 21210331151. The reversal of 21210331133 is 33113301212.

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 75568249 + 21134762884 = 8693^2 + 145378^2 .

It is a cyclic number.

It is not a de Polignac number, because 21210331133 - 2¹⁶ = 21210265597 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210331633) 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, 401210 + ... + 450987.

It is an arithmetic number, because the mean of its divisors is an integer number (5302802055).

Almost surely, 2^21210331133 is an apocalyptic number.

It is an amenable number.

21210331133 is a deficient number, since it is larger than the sum of its proper divisors (877087).

21210331133 is an equidigital number, since it uses as much as digits as its factorization.

21210331133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877086.

The product of its (nonzero) digits is 324, while the sum is 20.

Adding to 21210331133 its reverse (33113301212), we get a palindrome (54323632345).

The spelling of 21210331133 in words is "twenty-one billion, two hundred ten million, three hundred thirty-one thousand, one hundred thirty-three".