21335143331 has 4 divisors (see below), whose sum is σ = 21338748912. Its totient is φ = 21331537752.

The previous prime is 21335143243. The next prime is 21335143351. The reversal of 21335143331 is 13334153312.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21335143331 is a prime.

It is a super-2 number, since 2×21335143331² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21335143294 and 21335143303.

It is not an unprimeable number, because it can be changed into a prime (21335143351) 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, 1793900 + ... + 1805753.

It is an arithmetic number, because the mean of its divisors is an integer number (5334687228).

Almost surely, 2^21335143331 is an apocalyptic number.

21335143331 is a deficient number, since it is larger than the sum of its proper divisors (3605581).

21335143331 is an equidigital number, since it uses as much as digits as its factorization.

21335143331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3605580.

The product of its digits is 9720, while the sum is 29.

Adding to 21335143331 its reverse (13334153312), we get a palindrome (34669296643).

The spelling of 21335143331 in words is "twenty-one billion, three hundred thirty-five million, one hundred forty-three thousand, three hundred thirty-one".